CE port of Move "Authorize project access with external service" to Core

See merge request gitlab-org/gitlab-ce!26823

Move Contribution Analytics related spec in spec/features/groups/group_page_with_external_authorization_service_spec to EE

Add a length limit of 128 char to the user name field

See merge request gitlab-org/gitlab-ce!26146

Redirect Kubernetes installation to the charts docs

Closes #58870

See merge request gitlab-org/gitlab-ce!26159

Docs for combined ref pipelines

Closes #59495 and gitlab-ee#7380

See merge request gitlab-org/gitlab-ce!26762

pdate

Fall back to project repository type by default

Closes #60007

See merge request gitlab-org/gitlab-ce!27003

This makes sure that we always have a repository type when trying to
parse a repository from a path.

This is needed because sometimes we want to perform access checks as
if the project already existed, for example when creating a project on
push.

Before this we were only doing that when accessing git over http, this
makes sure it also works correctly when accessing git over SSH

[CE] Add mutually exclusive labels

See merge request gitlab-org/gitlab-ce!26804

Require all templates to use default stages

Closes #59992

See merge request gitlab-org/gitlab-ce!26954

Update Rails to 5.0.7.2

Closes #58963

See merge request gitlab-org/gitlab-ce!27022

Upgrade Gitaly to v1.32.0

See merge request gitlab-org/gitlab-ce!26989

Bump Helm to 2.13.1 and kubectl to 1.11.9

See merge request gitlab-org/gitlab-ce!26991

Extract remove due date spec to shared example

Closes #59570

See merge request gitlab-org/gitlab-ce!26922

Checkbox cannot be checked if preceded by a blockquote

Closes #58717

See merge request gitlab-org/gitlab-ce!26937

Add a prometheus proxy API per environment

Closes #58375

See merge request gitlab-org/gitlab-ce!26841

CE Improve project avatar settings

See merge request gitlab-org/gitlab-ce!26589

Resolve "Queries which return multiple series are not working correctly"

Closes #59323 and #59324

See merge request gitlab-org/gitlab-ce!26514

Corrects an issue whereby queries which return multiple series results
were not rendering as multiple data series on the metrics dashboard

Extract target branch quick action to shared example

Closes #59570

See merge request gitlab-org/gitlab-ce!26933

Bump rack gem to 2.0.7

See merge request gitlab-org/gitlab-ce!27033

Fix MWPS doesn't work for merge request pipelines

See merge request gitlab-org/gitlab-ce!26906

Extend CTE search optimisation to projects

Closes #55170

See merge request gitlab-org/gitlab-ce!26908

Autocorrect with RSpec/ExampleWording cop

See merge request gitlab-org/gitlab-ce!26817

- rewords examples starting with 'should'
- rewords examples starting with 'it'

Note: I had to manually fixup "onlies" to "only"

Fix race condition in ApplicationSettingImplementation.create_from_defaults

Closes #59162

See merge request gitlab-org/gitlab-ce!26319

Add documentation for custom build directories

See merge request gitlab-org/gitlab-ce!20427

This adds documentation for:

- `CI_BUILDS_DIR`,
- `CI_CONCURRENT_ID`,
- `CI_CONCURRENT_PROJECT_ID`,
- `GIT_CLONE_PATH`,
- `GIT_CLEAN_FLAGS`

Adding perf testdata for MR diff tab

See merge request gitlab-org/gitlab-ce!26660

Our templates are free to override the 'stages:'.
However, they should follow the convention to always include
'build', 'test', 'deploy' which are defaults when not defined.

Add a service to proxy calls to Prometheus API

See merge request gitlab-org/gitlab-ce!26840

- Also refactor the get and json_api_get methods so that the get method
can be reused by the new proxy method.
- The new proxy method makes no changes to the request to the prometheus
server and response from the prometheus server. This allows it to be
used as a proxy to the Prometheus server, hence the name.

Quarantine failing tests

See merge request gitlab-org/gitlab-ce!27036

Remove EE-specific parts from FilteredSearchManager (CE-backport)

See merge request gitlab-org/gitlab-ce!27016

(cherry picked from commit a4d0b2435ff132da9bb238fea95672a6ddfd084d)

Fix IDE file dropdown

Closes #60021

See merge request gitlab-org/gitlab-ce!27015

Truncate existing users names which exceed 128 characters
Include test for truncating users names