Refactor IssuableFinder to extract model-specific logic

See merge request gitlab-org/gitlab-ce!17236

Merge branch 'improve-codequality-job' into 'master'

See merge request gitlab-org/gitlab-ce!17263

CE port of changes made to the pipeline bundle in EE - Fixes typos and adds i18n

See merge request gitlab-org/gitlab-ce!17176

Reduce Spinach parallelization to 2 nodes and increase RSpec's to 28 nodes

See merge request gitlab-org/gitlab-ce!16713

Simplify the codequality job

See merge request gitlab-org/gitlab-ee!4602

Simplify database queries in MembersFinder and improve performance for Projects::ProjectMembersController#index

Closes #41461

See merge request gitlab-org/gitlab-ce!17190

Improve query performance for Dashboard::SnippetsController#index

Closes #42877

See merge request gitlab-org/gitlab-ce!17088

Move project pages spinach tests to Rspec

See merge request gitlab-org/gitlab-ce!17256

More dispatcher refactoring

See merge request gitlab-org/gitlab-ce!17232

Update wording docs labels

See merge request gitlab-org/gitlab-ce!17248

Do not count rails sql cache as queries in query limiting

See merge request gitlab-org/gitlab-ce!17253

By extracting a new `filter_items` method, we can override that in the
IssuesFinder and MergeRequestsFinder separately, so we don't need checks that
the model is the correct one, because we can just use the class we're in to know
that.

We can do the same for the VALID_PARAMS constant, by making it a class method.

https://gitlab.com/gitlab-org/gitlab-ce/issues/23036

Upgrade frontend build dependencies

Closes #41400

See merge request gitlab-org/gitlab-ce!17246

Update to jQuery 3.

Closes #33888

See merge request gitlab-org/gitlab-ce!16634

Refactor issue index filtered search

See merge request gitlab-org/gitlab-ce!16981