Align project and personal snippet abilities

Closes #39087

See merge request gitlab-org/gitlab!22500

Mostly a search and replace for *_project_snippet and *_personal_snippet
abilities across app and spec files. Replaced with just *_snippet and
falling back on the type of subject to determine which policies to
apply.

There are some less trivial changes included which relate to inferring
an abilities name from the subject class. Because ProjectSnippet is a
child of Snippet there is some special handling around the place. There
is perhaps potential to clean this up a bit as there is the same logic
spread out in various locations.

Various changes required after review

- Renamed before_action names
- Fixed snippet note mailer with spec
- Removed incorrect/unecessary policy parameter
- Fix personal snippet note policy spec

Resolve "Create feature spec for loading error details page"

Closes #36695

See merge request gitlab-org/gitlab!23543

Add feature specs covering the error tracking index
and the error tracking show page. Inculde expandable
stack traces in the feature spec.

Properly document how to run a custom gitaly build

See merge request gitlab-org/gitlab!23589

Add pages_access_level to projects API

Closes #30972

See merge request gitlab-org/gitlab!23176

New Crowdin translations

See merge request gitlab-org/gitlab!23499

[skip ci]

Stop NoMethodError happening for 1.16+ clusters

See merge request gitlab-org/gitlab!23149

The response for `/apis/extensions/v1beta1` does not have secrets,
serviceaccounts, services, not pods. It instead has deployments and
ingresses.

Verified from a real Kubernetes cluster. Run `kubectl proxy`, then
navigate to http://127.0.0.1:8001/apis/extensions/v1beta1

Prevent unnecessary Gitaly calls when rendering comment excerpts

See merge request gitlab-org/gitlab!23100

Remove inlined shared examples

See merge request gitlab-org/gitlab!23504

Merge branch '29987-revert-groups-overview-font-spacing-to-the-old-more-space-efficient-layout-2' into 'master'

Reduce whitespace in group list to keep more items in view

Closes #29987

See merge request gitlab-org/gitlab!21584

Tweak GPG cleanup attempts

See merge request gitlab-org/gitlab!23581

By default Retriable would only try 3 times. Which would never hit our
limit of 10s in sidekiq. Raising the number of tries means we'll only
be limited by the maximum runtime.

Setup to make monitoring date picker component reusable in other stages (1)

See merge request gitlab-org/gitlab!23383

Fixes: #30972

Convert Jest tests to use VTU in 'ee/spec/frontend/vue_shared'

Closes #197944

See merge request gitlab-org/gitlab!23413

Frontend: Use custom user name for service desk emails

See merge request gitlab-org/gitlab!22478

Track usage of merge request file header buttons

See merge request gitlab-org/gitlab!23523

Fix typo

See merge request gitlab-org/gitlab!23578

Fix code block in environment documentation

See merge request gitlab-org/gitlab!23397

Default the `creation of a Mattermost team` checkbox to false

See merge request gitlab-org/gitlab!23329

When creating a Mattermost group, the checkbox to create a team
for the group is set to checked by default.

Ensure that error tracking frontend only polls when required

See merge request gitlab-org/gitlab!23305

Document how to customize Auto DevOps values

See merge request gitlab-org/gitlab!23486

Add language tags to code blocks for linting

See merge request gitlab-org/gitlab!23470

Correcting broken links in the geo section

See merge request gitlab-org/gitlab!23567

Correct spelling in the user section

See merge request gitlab-org/gitlab!23557

Use consistent labeling for GitLab rake tasks

See merge request gitlab-org/gitlab!23550

Our specific rake tasks should start with ‘GitLab’
and be followed by the namespaces
eg: “GitLab | Elasticsearch | Create empty index”

Add changelog

By using the .gitlab/auto-deploy-values.yaml file

Allow users to sign-out on a read-only instance

See merge request gitlab-org/gitlab!23545