To avoid the use of slow queries, remove some deprecated methods and encourage
the use of ProjectFinder to find projects.

And use it in the API.

Now it is possible to combine the :non_public parameter. This might be useful
when a user wants to know the trending projects they are member of.

The ProjectsFinder and GroupFinder both support the same set of params. And the
`/api/v4/projects` and `/api/v4/group/:id/projects` also support the same set of
params. But they do not match the Finder params. So use a helper method to
transform them.

Instead of applying WHERE on a UNION, apply the WHERE on each of the seperate
SELECT statements, and do UNION on that.

Local tests with about 2_000_000 projects:
 - 1_500_000 private projects
 -    40_000 internal projects
 -   400_000 public projects

For the API endpoint `/api/v4/projects?visibility=private` the slowest query was:

```sql
SELECT "projects".*
FROM "projects"
WHERE ...
```

The original query took 1073.8ms.
The query refactored to UNION of SELECT/WHERE took 2.3ms.

The original query was:

```sql
SELECT "projects".*
FROM "projects"
WHERE "projects"."pending_delete" = $1
  AND (projects.id IN
         (SELECT "projects"."id"
          FROM "projects"
          INNER JOIN "project_authorizations" ON "projects"."id" = "project_authorizations"."project_id"
          WHERE "projects"."pending_delete" = 'f'
            AND "project_authorizations"."user_id" = 23
          UNION SELECT "projects"."id"
          FROM "projects"
          WHERE "projects"."visibility_level" IN (20,
                                                  10)))
  AND "projects"."visibility_level" = $2
  AND "projects"."archived" = $3
ORDER BY "projects"."created_at" DESC
LIMIT 20
OFFSET 0 [["pending_delete", "f"],
       ["visibility_level", 0],
       ["archived", "f"]]
```

The refactored query:
```sql
SELECT "projects".*
FROM "projects"
WHERE "projects"."pending_delete" = $1
  AND (projects.id IN
         (SELECT "projects"."id"
          FROM "projects"
          INNER JOIN "project_authorizations" ON "projects"."id" = "project_authorizations"."project_id"
          WHERE "projects"."pending_delete" = 'f'
            AND "project_authorizations"."user_id" = 23
            AND "projects"."visibility_level" = 0
            AND "projects"."archived" = 'f'
          UNION SELECT "projects"."id"
          FROM "projects"
          WHERE "projects"."visibility_level" IN (20,
                                                  10)
            AND "projects"."visibility_level" = 0
            AND "projects"."archived" = 'f'))
ORDER BY "projects"."created_at" DESC
LIMIT 20
OFFSET 0 [["pending_delete", "f"]]
```

Instead of trying to do the heavy lifting in the API itself, use the existing
features of the ProjectFinder.

The `starred` parameter couldn't be used in combination with `trending` or
`non_public`. But this is changed now.

Add a scope to search for the projects that are starred by a certain user.

The ProjectFinder supports the `non_public` parameter. This can be used to find
only projects the user is member of.

Because this order makes more sense and makes the code easier to read.

To avoid passing parameters double, move all filtering to the `present_projects`
helper.

The helper will be modified in V4, so copy the original to V4 to keep the
current behavior in V3.

Resolve "Allow to disable username on checkout url"

Closes #30410 and #30174

See merge request !11792

Remove extra bottom padding on Job log page

Closes #30502

See merge request !11791

Enable Gitaly by default in GitLab 9.3

Closes gitaly#242

See merge request !11796

Avoid crash when trying to parse string with invalid UTF-8 sequence

See merge request !11770

Don’t create comment on JIRA if link already exists

Closes #25373

See merge request !11485

`canEdit` changes for conditional remove button on filtered search -- EE backport

Closes gitlab-ee#2433

See merge request !11696

Disable sub_group_issuables_spec.rb for mysql

Closes #33057

See merge request !11795

Make `ActiveRecord::Migrator` idempotent again in test environment

Closes #33030

See merge request !11762

Fix alignment of tree symbols in merge requests

Closes #29590

See merge request !11761

Merge branch '19107-404-when-creating-new-milestone-or-issue-for-project-that-has-issues-disabled' into 'master'

'New issue'/'New merge request' dropdowns should show only projects with issues/merge requests feature enabled

Closes #19107

See merge request !11754

Merge branch '33048-markdown-rendering-of-md-files-has-ceased-to-display-latex-equations' into 'master'

Fix math rendering on blob pages

Closes #33048

See merge request !11793

Merge branch '33032-invalid-you-directly-addressed-yourself-todo-when-using-unsubscribe' into 'master'

Resolve "Invalid 'You directly addressed yourself' TODO when using `/unsubscribe`"

Closes #33032

See merge request !11788

Fix omniauth-google-oauth2 dependencies in Gemfile.lock

Closes #32653

See merge request !11787

`renderGFM` adds the correct syntax highlighting class and triggers KaTeX if
required.

Signed-off-by: Rémy Coutable <remy@rymai.me>

This partially reverts be25bbc4.
Signed-off-by: Rémy Coutable <remy@rymai.me>

This reverts commit c425f366, reversing
changes made to 82f6c0f5.
Signed-off-by: Rémy Coutable <remy@rymai.me>

Use 'sudo bash' when adding nodesource repository

See merge request !10527

Resolve "Browser notifications for pipeline running in a MR is gone"

Closes #32916

See merge request !11734

Set head pipeline when creating merge requests

See merge request !11669

The /unsubscribe slash command means that we check if the current user is
subscribed to the issuable without having an explicit subscription. That means
that we use the UserParser to find references to them in the notes.

The UserParser (and all parsers inheriting from BaseParser) use RequestStore to
cache ActiveRecord objects, so that we don't need to load the User object each
time, if we're parsing references a bunch of times in the same request.

However, it was always returning _all_ of the previously cached items, not just
the ones matching the IDs passed. This would mean that we did two runs through
with UserParser if you were mentioned in a comment, and then mentioned someone
else in your comment while using /unsubscribe:

1. Because /unsubscribe was used, we see if you were mentioned in any comments.
2. Because you mentioned someone, we find them - but we would also get back your
   user, even if you didn't mention yourself. This would have the effect of
   creating a mention or directly addressed todo for yourself incorrectly.

The fix is simple: only return values from the cache matching the IDs passed.

Signed-off-by: Rémy Coutable <remy@rymai.me>

Update looks job log

Closes #30117

See merge request !11663