A nonce-based Content-Security-Policy thwarts XSS attacks by allowing
inline JavaScript to execute if the script nonce matches the header
value. Rails 5.2 supports nonce-based Content-Security-Policy headers,
so provide configuration to enable this and make it work.

To support this, we need to change all `:javascript` HAML filters to the
following form:

```
= javascript_tag nonce: true do
  :plain
    ...
```

We use `%script` throughout our HAML to store JSON and other text, but
since this doesn't execute, browsers don't appear to block this content
from being used and require the nonce value to be present.

Use Rails 5.2 Redis caching store

Closes #64794

See merge request gitlab-org/gitlab-ce!30966

Fix links to unassigned, low weight issues for first time contributors

See merge request gitlab-org/gitlab-ce!31485

(Really) Fix Ruby 2.5 compatibility for diverging counts of branches

Closes #64143

See merge request gitlab-org/gitlab-ce!31491

Fix Admin area user access level radio button labels

See merge request gitlab-org/gitlab-ce!31154

EE: Fix Admin area user access level radio button labels

See merge request gitlab-org/gitlab-ee!14844

In the admin user edit form, access level radio button labels didn't have
the correct 'for' value. Clicking on the label did not select the radio
button. This makes usability a bit nicer since the click area is increased
when the label is clickable.

This is the first step in providing a fault-tolerant and distributed
Redis caching store. We disable compression to avoid introducing a
change that could have an adverse effect in production.

Note that we won't be able to take advantage of the fault-tolerance and
distributed features yet until we solve
https://gitlab.com/gitlab-org/gitlab-ce/issues/64829.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/64794

!31480 does not fully restore compatibility because another Ruby 2.6
feature besides `Enumerable#filter` was used in commit ca5cd7b7. The use
of `Enumerable#to_h`'s block is now replaced by an explicit
`Enumerable#map` call.

Error message:

	TypeError (wrong element type Gitlab::Git::Branch at 0 (expected array)):
  	app/controllers/projects/branches_controller.rb:53:in `to_h'

See https://bugs.ruby-lang.org/issues/15143.

Fixes #64143.

Remove validation of MR level approval rules in merge requests

See merge request gitlab-org/gitlab-ee!14968

In the admin user edit form, access level radio button labels didn't have
the correct 'for' value. Clicking on the label did not select the radio
button. This makes usability a bit nicer since the click area is increased
when the label is clickable.

Resolve "Add padding to "merged by" widget"

Closes #64831

See merge request gitlab-org/gitlab-ce!30972

This reverts commit c3751046d217008404a0bd371e59d6ffd6734923.

UX fixes for projects dropdown filter

See merge request gitlab-org/gitlab-ee!14890

Update dependency @gitlab/ui to v5.14.0

See merge request gitlab-org/gitlab-ce!31482

Fix admin notes internationalization text

See merge request gitlab-org/gitlab-ee!15001

Add example to plugins file

See merge request gitlab-org/gitlab-ce!30508

Add description how to set custom CI file

See merge request gitlab-org/gitlab-ce!31445

Fix error on project name

See merge request gitlab-org/gitlab-ce!31471

Add project path to sql query to build proper path

[ci skip]

[ci skip]

[ci skip]

Resolve "API endpoint to list the Docker images/tags of a group"

See merge request gitlab-org/gitlab-ce!30817

API endpoints for requesting container repositories
and container repositories with their tag information
are enabled for users that want to specify the group
containing the repository rather than the specific project.

Make thumbnails in design lists not distorted

See merge request gitlab-org/gitlab-ee!14670

This change basically makes use of flexbox features
to have the images be vertically centered instead of
stretched vertically, which was distorting images'
original ratio.

Also updates the jest snapshots with the new markup.

This removes `MergeRequest#validate_approval_rule_source` which
was responsible to check whether the MR level approval rules
matches the existing project level rules.

Added the validation in `ApprovalMergeRequestRule` to check if the
project of `approval_project_rule` matches the merge request's
project. This way we can ensure that the source rule should still
be in the same project.

This will make the logic simpler for the upcoming API to create
MR level approval rules.