Resolve "Activity entries are not loaded fully to cover full window's height"

## What does this MR do?

Fixes a bug in which a browser window large enough to encompass the default number of items in an auto-loading endless-scroll list could not trigger the loading of additional items.

## Are there points in the code the reviewer needs to double check?

I refactored activities.js and pager.js into es6 syntax while I was investigating the issue.  No changes were made other than some es6 flourishes and eslint conformity, so nothing should be effected, but perhaps best to double check other pages which utilize these scripts.

## Screenshots (if relevant)

![endless-scroll-fixed](/uploads/b672b606826af745528c209ab6cfe95c/endless-scroll-fixed.gif)

## Does this MR meet the acceptance criteria?

- [x] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) added
- Tests
  - [x] All builds are passing
- [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if it does - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?


Closes #24499

See merge request !7608

Fix errors happening when source branch of merge request is removed and then restored

See merge request !7568

Adds a flag to reflect whether or not there is data in cycle analytics

See merge request !7622

Remove v-html

## What does this MR do?
Uses string interpolation instead of `v-html` to prevent xss attacks.

## Does this MR meet the acceptance criteria?

- [ ] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) added
- [ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- Tests
  - [ ] Added for this feature/bug
  - [ ] All builds are passing
- [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if it does - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?

See merge request !7616

Grapify the projects snippet API

Related to https://gitlab.com/gitlab-org/gitlab-ce/issues/22928

See merge request !7621

nothing to merge in merge request page

Smarter cache invalidation

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/23550

See merge request !7360

Allow JIRA references for project snippets

closes #24303

See merge request !7541

Added permissions per stage to cycle analytics endpoint

See merge request !7613

Merge branch '24552-js-environment-timeago-is-not-rendered-and-text-shows-object-object-in-mr-widget' into 'master'

Fix timeago rendering for environment timeago

## What does this MR do?

## Are there points in the code the reviewer needs to double check?

## Why was this MR needed?

## Screenshots (if relevant)

## Does this MR meet the acceptance criteria?

- [ ] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) added
- [ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- Tests
  - [ ] Added for this feature/bug
  - [ ] All builds are passing
- [ ] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [ ] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [ ] Branch has no merge conflicts with `master` (if it does - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?


Closes #24552

See merge request !7539

Merge branch '24616-mr-shows-the-build-for-this-merge-request-failed-although-builds-still-running' into 'master'

Resolve "MR shows "The build for this merge request failed" although builds still running"

Closes #24616

See merge request !7579

This refactors repository caching so it's possible to selectively
refresh certain caches, instead of just expiring and refreshing
everything.

To allow this the various methods that were cached (e.g. "tag_count" and
"readme") use a similar pattern that makes expiring and refreshing
their data much easier.

In this new setup caches are refreshed as follows:

1. After a commit (but before running ProjectCacheWorker) we expire some
   basic caches such as the commit count and repository size.

2. ProjectCacheWorker will recalculate the commit count, repository
   size, then refresh a specific set of caches based on the list of
   files changed in a push payload.

This requires a bunch of changes to the various methods that may be
cached. For one, data should not be cached if a branch used or the
entire repository does not exist. To prevent all these methods from
handling this manually this is taken care of in
Repository#cache_method_output. Some methods still manually check for
the existence of a repository but this result is also cached.

With selective flushing implemented ProjectCacheWorker no longer uses an
exclusive lease for all of its work. Instead this worker only uses a
lease to limit the number of times the repository size is updated as
this is a fairly expensive operation.

Do not create TODO when build is allowed to fail

## What does this MR do?

Do not create a TODO when build that failed is allowed to fail.

## Does this MR meet the acceptance criteria?

- [x] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- Tests
  - [x] Added for this feature/bug
  - [ ] All builds are passing

## What are the relevant issue numbers?

Closes #22280

See merge request !7618

Also allow merge request to be merged with skipped pipeline and the
"only allow merge when pipeline is green" feature enabled
Signed-off-by: Rémy Coutable <remy@rymai.me>

Backport some changes done from Time Tracking feature in EE.

See merge request !7604

Grapify the users API

Certain endpoints return different entities based on which user issues the request. Right now, I am not aware how to specify multiple entities as part of the description block of the endpoint. @rymai Do you know something about that.

## What are the relevant issue numbers?

Related to #22928

See merge request !7147

This reverts commit f913170e.

Remove bashism from scripts/prepare_build.sh

Make `scripts/prepare_build.sh` an sh, rather than bash, script

Write once, run everywhere. Even alpine.

See merge request !7561

Initializing Rugged objects is way too expensive just to check if a
repository exists. Even though we cache this data once in a while we
have to refresh this. On GitLab.com we have seen Repository#exists?
taking up to _1 minute_ to complete in the absolute worst case, though
usually it sits around a second or so.

Using File.exist? to instead check if $GIT_DIR/refs exists is a much
faster way of checking if a repository was initialized properly.

This moves the logic of detecting special repository files (e.g. a
README or a Koding configuration file) to a single class:
Gitlab::FileDetector. Moving this logic into a single place allows this
to be re-used more easily.

This commit also changes Repository#gitlab_ci_yaml so that its cached
similar to other data (e.g. the Koding configuration file).

Add constraints to group id in routing

To prevent 404 when visit page like https://gitlab.com/groups/group.with.dot/activity

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/24622

See merge request !7614

Add API endpoint for creating a pipeline

Fixes #23468

See merge request !7209

Allow to block JIRA events for commits and merge requests

implements #5541 

See merge request !7469