If migrations are pending, make CurrentSettings use existing values and populate missing columns with defaults

master was failing because `ApplicationSetting.create_from_defaults` attempted
to write to a column that did not exist in the database. This occurred in a
`rake db:migrate` task, which was unable to perform the migration that would
have added the missing column in the first place.

In 9.3 RC2, we also had a bug where password sign-ins were disabled because
there were many pending migrations. The problem occurred because
`fake_application_settings` was being returned with an OpenStruct that did not
include the predicate method `signup_enabled?`. As a result, the value would
erroneously return `nil` instead of `true`. This commit uses the values of the
defaults to mimic this behavior.

This commit also refactors some of the logic to be clearer.

This reverts commit ad521bde, reversing
changes made to 3a38e5f1.

Fix eslint import resolver in Atom v1.18.0

See merge request !12238

Changed utilites imports from ~ to relative paths

Closes #33485

See merge request !12026

Partially revert 1e8dbd46

See merge request !12236

Remove unnecessary spec file

See merge request !12233

Increase karma socket timeout

Closes #33735

See merge request !12226

Fixes boards_spec failure

Closes #33614

See merge request !12230

See https://gitlab.com/gitlab-org/gitlab-ce/issues/33736#note_32561501

Fixed overflow on mobile screens for the slash commands

Closes #29013

See merge request !12100

Backport panels.scss styles from EE

See merge request !12206

Add table for files in merge request diffs

See merge request !12047

Show private subgroups if member of parent group

Closes #32135

See merge request !11764

Call Capybara.reset_sessions! before block_and_wait_for_requests_complete

Closes #33779

See merge request !12224

This adds an ID-less table containing one row per file, per merge request
diff. It has a column for each attribute on Gitlab::Git::Diff that is serialised
currently, with the advantage that we can easily query the attributes of this
new table.

It does not migrate existing data, so we have fallback code when the legacy
st_diffs column is present instead. For a merge request diff to be valid, it
should have at most one of:

* Rows in this new table, with the correct merge_request_diff_id.
* A non-NULL st_diffs column.

It may have neither, if the diff is empty.

Closes #33614

Rename "Slash commands" to "Quick actions"

Closes #27070

See merge request !11811

Remove issuable drag and drop and sorting from milestone view

Closes #20900

See merge request !11950

Add missing bottom border to blame age legend

Closes #33739

See merge request !12205

Missing translations for the project & repository pages.

Closes #33420

See merge request !12052

capybara/rspec already calls Capybara.reset_sessions! in an
`after` hook, but `block_and_wait_for_requests_complete` is called
before it so by calling it explicitely here, we prevent any new
requests from being fired.
See
https://github.com/teamcapybara/capybara/blob/ffb41cfad620de1961bb49b1562a9fa9b28c0903/lib/capybara/rspec.rb#L20-L25Signed-off-by: NRémy Coutable <remy@rymai.me>

Document the Delete Merged Branches functionality

See merge request !12217

Create responsive mobile view for pipelines table

Closes #31415

See merge request !12171

Add French translations for Cycle Analytics, Project, and Repository pages.

Closes #32998 and #33140

See merge request !12200

Speed up used languages calculation on charts page

See merge request !12212

set ENV['prometheus_multiproc_dir'] in config/boot.rb instead of config.ru

See merge request !12201