Docs: Resolve issues with issue docs

Closes #64102

See merge request gitlab-org/gitlab-ce!30337

Change csv import section to bullet list, add back missing
bulk import section, and resolve minor issues raised in
https://gitlab.com/gitlab-org/gitlab-ce/issues/64102

Use GitlabUploader#filename when generating upload URLs

See merge request gitlab-org/gitlab-ce!29915

E2E Test to check XSS issue in @mentions autocomplete

Closes #41089

See merge request gitlab-org/gitlab-ce!29884

Docs: Full Copy Edit and Refactor of Issues docs

Closes #60767

See merge request gitlab-org/gitlab-ce!27553

After review, heading was changed and links to
it needed to be updated, and minor tweaks to
the issues docs such as note formatting

Resolve "SSO enforcement should enforce on subgroups"

Closes #12189

See merge request gitlab-org/gitlab-ee!14364

This change initiates SSO login when an unauthanticated user tries
to access a group, subgroup or a project when the group_saml feature is
enabled.

Cache Flipper feature flags in L1 and L2 caches

See merge request gitlab-org/gitlab-ce!30276

Resolve "Do not update `updated_at` on an epic when reordering it."

Closes #12459

See merge request gitlab-org/gitlab-ee!14441

Updates the yaml docs to match the environment docs regarding `GIT_STRATEGY=none`

See merge request gitlab-org/gitlab-ce!30283

Docs: Update Auto Deploy link to page instead of redirect

See merge request gitlab-org/gitlab-ce!30325

Remove duplicate info from API docs

See merge request gitlab-org/gitlab-ee!14535

In https://gitlab.com/gitlab-com/gl-infra/production/issues/928, we saw
a significant amount of network traffic and CPU usage due to Redis
checking feature flags via Flipper. Since these flags are hit with every
request, the overhead becomes significant. To alleviate Redis overhead,
we now cache the data in the following way:

* L1: A thread-local memory store for 1 minute
* L2: Redis for 1 hour

Notes that `GIT_STRATEGY` should be set to `none` so that the
job doesn't fail when triggered automatically when the branch
is deleted.

Backport EE MR that improves end-to-end tests

See merge request gitlab-org/gitlab-ce!30320

Limit amount of JUnit tests returned

Closes #64035

See merge request gitlab-org/gitlab-ce!30274

EE: Limit amount of JUnit tests returned

See merge request gitlab-org/gitlab-ee!14534

Re-work release end-to-end test

See merge request gitlab-org/gitlab-ee!14525

De-quarantine test to see if it's fixed

Closes gitlab-org/quality/nightly#70

See merge request gitlab-org/gitlab-ee!14524

Currently, we do not cap amount of tests returned to frontend,
thus in some extreme cases we can see a MBs of data stored in Redis.

This adds an upper limit of 100 tests per-suite.

We will continue showing the total counters correctly,
but we will limit amount of tests that will be presented.

Currently, we do not cap amount of tests returned to frontend,
thus in some extreme cases we can see a MBs of data stored in Redis.

This adds an upper limit of 100 tests per-suite.

We will continue showing the total counters correctly,
but we will limit amount of tests that will be presented.

Rename Release groups in issue_workflow.md

See merge request gitlab-org/gitlab-ce!30293

Change occurrence of Sidekiq::Testing.inline!

Closes #22991

See merge request gitlab-org/gitlab-ce!29890

- Change it to perform_enqueued_jobs

We don't need to find the filename from the remote URL

https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/14533

Fix order-dependent spec failure in appearance_spec.rb

Closes #64083

See merge request gitlab-org/gitlab-ce!30323