Enables frozens string for the following:

* lib/gitlab/conflict/**/*.rb
* lib/gitlab/cross_project_access/**/*.rb
* lib/gitlab/cycle_analytics/**/*.rb
* lib/gitlab/data_builder/**/*.rb
* lib/gitlab/database/**/*.rb
* lib/gitlab/dependency_linker/**/*.rb
* lib/gitlab/diff/**/*.rb
* lib/gitlab/downtime_check/**/*.rb
* lib/gitlab/email/**/*.rb
* lib/gitlab/etag_caching/**/*.rb

Partially addresses gitlab-org/gitlab-ce#47424.

Add a helper method to append path to a base URL

See merge request gitlab-org/gitlab-ce!22854

Little typo in markdown.md

See merge request gitlab-org/gitlab-ce!22851

In Ruby 2.4, `URI.join("http://test//", "a").to_s` will
remove the double slash, however it's not the case in
Ruby 2.5. Using chomp should work better for the intention,
as we're not trying to allow things like ../ or / paths
resolution.

This helper method append path to host, making sure
there's one single slash as path separator.

Rails5: fix mysql milliseconds issue in deployment model specs

See merge request gitlab-org/gitlab-ce!22850

Add AWS installation docs

Closes #49501

See merge request gitlab-org/gitlab-ce!20778

Extract code into IssueBoardEntity / serializer

See merge request gitlab-org/gitlab-ce!22760

Renders a warning block for archived job

Closes #53535

See merge request gitlab-org/gitlab-ce!22811

Allow single letter external issue IDs

Closes #52803

See merge request gitlab-org/gitlab-ce!22717

Stop Repository#fetch_remote from using Gitlab::Shell

See merge request gitlab-org/gitlab-ce!22635

CE MR for Group SAML SSO badges

See merge request gitlab-org/gitlab-ce!22587

Fixed label removal from issue

Closes #51052

See merge request gitlab-org/gitlab-ce!22762

Disable stop environment button while deployment is running

See merge request gitlab-org/gitlab-ce!22805

Delegate storage health check to Gitaly's health check

Closes gitaly#1336

See merge request gitlab-org/gitlab-ce!22063

Add packages section to CE config file

See merge request gitlab-org/gitlab-ce!22151

Resolve "Redesign activity feed"

Closes #49403

See merge request gitlab-org/gitlab-ce!22217

Restore changes from:

See merge request gitlab-org/gitlab-ce!22838

Backport support project security dashboard changes

See merge request gitlab-org/gitlab-ce!22824

This indirection doesn't provide any value, so remove it

Change life cycle of `deployments` records in order to make it a stateful object

See merge request gitlab-org/gitlab-ce!22380

Revert Drop gcp_clusters table

See merge request gitlab-org/gitlab-ce!22837

Removes 'experimental' label from cluster views

See merge request gitlab-org/gitlab-ce!22550

Add background migration for Kubernetes Namespaces

See merge request gitlab-org/gitlab-ce!22433

Merge branch '7737-ci-pipeline-view-slowed-down-massivly-if-security-tabs-has-many-entries' into 'master'

Improve performance of rendering large reports

See merge request gitlab-org/gitlab-ce!22835

Renders unescaped `sprinft` string

Closes #53533

See merge request gitlab-org/gitlab-ce!22807

190afc62

It was lost during a conflict resolution

Render index.* like README.* when it's present in a directory

Closes #18933

See merge request gitlab-org/gitlab-ce!22639

Instead of rendering all report items in 4 big lists, we make use of
vue-virtual-scroll-list and render only few dozens at once. This
improves the performance in several metrics:

- Initial load time
- Memory Pressure
- CPU Load
- DOM node count

In an example with around 11k reported security vulnerabilities:

- Initial load time: 27s -> 4.1s
- Memory Pressure: ~750 MB -> ~270 MB
- CPU Load (time spent on executing JS/Rendering): 22s -> 2.5s
- DOM node count: 430k -> 7k up to 30k while scrolling