[QA] Toggle Gitaly N+1 detector via feature flag and run tests

Closes gitlab-qa#374

See merge request gitlab-org/gitlab-ce!26060

First attempt at allowing a feature flag to be set via the command line
when running tests. This will enable the flag, run the tests, and then
disable the flag.

Using OptionParser meant changing how scenarios get the instance
address, so this also allows the address to be set as a command line
option. It's backwards compatible (you can still provide the address
as the command line option after the scenario)

Update bootstrap to 4.3.1

Closes #52091

See merge request gitlab-org/gitlab-ce!25911

Expand and improve autofetch of endpoint section

See merge request gitlab-org/gitlab-ce!26303

Recommend disabling NFS server delegation

See merge request gitlab-org/gitlab-ce!26668

Prepares suggestion implementation for multi-line support

See merge request gitlab-org/gitlab-ce!26057

Externalize strings in controllers

See merge request gitlab-org/gitlab-ce!26420

- concerns
- dashboard
- groups
- import

Adds the groundwork needed in order to persist multi-line suggestions,
while providing the parsing strategy which will be reused for the
**Preview** as well.

Add API access check to Graphql

Closes #58547

See merge request gitlab-org/gitlab-ce!26570

Check if user can access API on GraphqlController

See https://gitlab.com/gitlab-org/design.gitlab.com/issues/242

Bootstrap 4.3.1 introduced sanitation for HTML popovers / tooltips. The
rules are rather strict, so we extend the default whitelists with safe
attributes / tags.

Removes EE differences for environments_table

Closes gitlab-ee#10714

See merge request gitlab-org/gitlab-ce!26655

Removes EE differences for stage_column_component_spec

Closes gitlab-ee#10719

See merge request gitlab-org/gitlab-ce!26659

Removes EE differences for pipelines_details_bundle

Closes gitlab-ee#10711

See merge request gitlab-org/gitlab-ce!26654

Removes EE differences for environments.scss

Closes gitlab-ee#10708

See merge request gitlab-org/gitlab-ce!26648

Remove top-level mount from note_form_spec.js

Closes #59114

See merge request gitlab-org/gitlab-ce!26616

Add seed for personal access token

Closes #59500

See merge request gitlab-org/gitlab-ce!26582

Update the MR template for security MRs

Closes gitlab-org/release/framework#256

See merge request gitlab-org/gitlab-ce!26658

This makes two changes to the template:

1. EE MRs are now always required (see
   https://gitlab.com/gitlab-org/release/framework/issues/256 for a
   backstory).

2. We clarify that a release manager is not a suitable reviewer for
   security merge requests.

Optimize /api/v4/projects endpoint for visibility level

See merge request gitlab-org/gitlab-ce!26481

Unquarantine previously failing auto devops test

See merge request gitlab-org/gitlab-ce!26641

The smoke test for AutoDevOps was previously failing.
This test is now passing and ready to be unquarantined

Removes extra space in CE

Closes gitlab-ee#10710

See merge request gitlab-org/gitlab-ce!26649

Removes EE differences for issuable.scss

See merge request gitlab-org/gitlab-ce!26588

If the requested visibility levels contains only public and/or internal,
omitting private, then we can skip the EXISTS query to search for
private projects for the user.

Previously when a user requested a list of projects,
`Project#public_or_visible_to_user` would search all authorized projects
and public/internal projects as well. However, when a user requests a
specific `visibility_level` (e.g. private), that should reduce the
search space, and we shouldn't need to load public/internal projects.

Improves https://gitlab.com/gitlab-org/gitlab-ce/issues/59329

Fixes link in artifacts breadcrumb

Closes #59502

See merge request gitlab-org/gitlab-ce!26592

The link to the job page was not set properly,
with this commit it links to the correct job page.

Copy missing test in assignees_spec.js from EE

Closes gitlab-ee#6641

See merge request gitlab-org/gitlab-ce!26618

Remove expand diff to full file feature flag

See merge request gitlab-org/gitlab-ce!26614