The automatic merging code used `--strategy=ours`, which turned out to
be incorrect; instead we wanted `--strategy=recursive
--strategy-option=ours`. This small difference results in merging
throwing away _all_ EE changes in favour of CE changes, instead of only
doing this for conflicts.

This commit ensures that EE has all the appropriate changes. The diff
was generated by cherry picking all merge commits made since two days
ago, picking them with `--strategy=recursive --strategy-option=ours`.

EE Fix issuables sort direction button parameters

See merge request gitlab-org/gitlab-ee!8826

Revert unnecessary changes to CI configuration

See merge request gitlab-org/gitlab-ee!8822

Removed duplicate line from SelectsHelper

See merge request gitlab-org/gitlab-ee!8823

EE: Resolve various database deprecation warnings

See merge request gitlab-org/gitlab-ee!8818

Support older NGINX version forwarding the client certificate for smartcard auth

See merge request gitlab-org/gitlab-ee!8784

Resolve various database deprecation warnings

See merge request gitlab-org/gitlab-ce!23772

Fix labels parameter being deleted from filter
when clicking sort direction button on issues/merge requests search bar.

This was added by accident due to a CE and EE MR both modifying this
file in a slightly different way.

This reverts commit 2fc61b12, reversing
changes made to e26d96d3.

Refactor Project#create_or_update_import_data

See merge request gitlab-org/gitlab-ce!23701

Move more EE specific code out of CE code

See merge request gitlab-org/gitlab-ee!8424

Allow matching only the repo-root for CODEOWNERS

Closes #8593

See merge request gitlab-org/gitlab-ee!8708

Do not save user preferences on read-only mode

Closes #55024

See merge request gitlab-org/gitlab-ce!23698

This fixes two cases of EE specific code extending
ActiveRecord::Migration, instead of extending
ActiveRecord::Migration[4.2].

The use of `table_exists?` in the opclasses support initializer triggers
a deprecation warning. Using `data_source_exists?` removes this
deprecation.

Extending from ActiveRecord::Migration is deprecated, but was still used
in a bunch of places.

The use of `table_exists?` in the opclasses support initializer triggers
a deprecation warning. Using `data_source_exists?` removes this
deprecation.

Move EE code out of app/helpers and into ee/app/helpers

See merge request gitlab-org/gitlab-ee!8702

Instance level Maven endpoint (second attempt)

Closes #7769

See merge request gitlab-org/gitlab-ee!8757

Extending from ActiveRecord::Migration is deprecated, but was still used
in a bunch of places.

Resolve "Empty state shown when the group security dashboard request fails"

Closes #8704

See merge request gitlab-org/gitlab-ee!8703

Add basic implementation of CI/CD bridge job

See merge request gitlab-org/gitlab-ce!23730

Wait for push before trying to create a new MR

See merge request gitlab-org/gitlab-ce!23745

Fix creation query for pools repository

See merge request gitlab-org/gitlab-ce!23729

Send a notification email on mirror update errors

Closes #54650

See merge request gitlab-org/gitlab-ce!23595

[EE] Send a notification email on mirror update errors

See merge request gitlab-org/gitlab-ee!8801