Enhance performance of counting local Uploads

Closes gitlab-ee#6070

See merge request gitlab-org/gitlab-ce!22522

Comment on any expanded diff line on MRs

See merge request gitlab-org/gitlab-ce!22398

Copy changes for abuse clarity

Closes #51589

See merge request gitlab-org/gitlab-ce!22148

(EE Port) Assign approvers based on code owners

See merge request gitlab-org/gitlab-ce!22513

Fix broken link to Vagrant box

See merge request gitlab-org/gitlab-ce!22859

Resolve "`parallel` job keyword MVC"

Closes #21480

See merge request gitlab-org/gitlab-ce!22631

Now the files are identical again compared to EE.

These are backported from
https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/5050

Add an index to the `store` column on `uploads`. This makes counting
local uploads faster.

Also, there is no longer need to check for objects with `store = NULL`.
See https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/18557

---

### Query plans

Query:

```sql
SELECT COUNT(*)
FROM "uploads"
WHERE ("uploads"."store" = ? OR "uploads"."store" IS NULL)
```

#### Without index

```
gitlabhq_production=# EXPLAIN ANALYZE SELECT uploads.* FROM uploads WHERE (uploads.store = 1 OR uploads.store IS NULL);
                                                  QUERY PLAN
---------------------------------------------------------------------------------------------------------------
 Seq Scan on uploads  (cost=0.00..601729.54 rows=578 width=272) (actual time=6.170..2308.256 rows=545 loops=1)
   Filter: ((store = 1) OR (store IS NULL))
   Rows Removed by Filter: 4411957
 Planning time: 38.652 ms
 Execution time: 2308.454 ms
(5 rows)
```

#### Add index

```
gitlabhq_production=# create index uploads_tmp1 on uploads (store);
CREATE INDEX
```

#### With index

```
gitlabhq_production=# EXPLAIN ANALYZE SELECT uploads.* FROM uploads WHERE (uploads.store = 1 OR uploads.store IS NULL);
                                                          QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------
 Bitmap Heap Scan on uploads  (cost=11.46..1238.88 rows=574 width=272) (actual time=0.155..0.577 rows=545 loops=1)
   Recheck Cond: ((store = 1) OR (store IS NULL))
   Heap Blocks: exact=217
   ->  BitmapOr  (cost=11.46..11.46 rows=574 width=0) (actual time=0.116..0.116 rows=0 loops=1)
         ->  Bitmap Index Scan on uploads_tmp1  (cost=0.00..8.74 rows=574 width=0) (actual time=0.095..0.095 rows=545 loops=1)
               Index Cond: (store = 1)
         ->  Bitmap Index Scan on uploads_tmp1  (cost=0.00..2.44 rows=1 width=0) (actual time=0.020..0.020 rows=0 loops=1)
               Index Cond: (store IS NULL)
 Planning time: 0.274 ms
 Execution time: 0.637 ms
(10 rows)
```

Closes https://gitlab.com/gitlab-org/gitlab-ee/issues/6070

Add dynamic timer to delayed jobs

See merge request gitlab-org/gitlab-ce!22382

Fix links to product features

See merge request gitlab-org/gitlab-ce!22860

Remove gitlab-ui loading icon from global

See merge request gitlab-org/gitlab-ce!22724

Re-implemented image commenting on diffs

Closes #48956

See merge request gitlab-org/gitlab-ce!22443

Merge branch '52771-ldap-users-can-t-choose-private-or-internal-when-creating-a-new-group' into 'master'

Fix new group visibility form for non-admins

Closes #52771

See merge request gitlab-org/gitlab-ce!22468

CE port: Remove instance autocomplete_service variable

See merge request gitlab-org/gitlab-ce!22847

Update issue_workflow.md: team labels

See merge request gitlab-org/gitlab-ce!22800

CI/CD coverage docs: fix pytest-cov regex

Closes #48613

See merge request gitlab-org/gitlab-ce!22842

Fix bug with wiki page create message

Closes #50890

See merge request gitlab-org/gitlab-ce!22849

Fix statement timeouts in RemoveRestrictedTodos migration

Closes #52649

See merge request gitlab-org/gitlab-ce!22795

Use merge request prefix symbol in event feed title

Closes #36267

See merge request gitlab-org/gitlab-ce!22449

Add a helper method to append path to a base URL

See merge request gitlab-org/gitlab-ce!22854

Little typo in markdown.md

See merge request gitlab-org/gitlab-ce!22851

In Ruby 2.4, `URI.join("http://test//", "a").to_s` will
remove the double slash, however it's not the case in
Ruby 2.5. Using chomp should work better for the intention,
as we're not trying to allow things like ../ or / paths
resolution.

This helper method append path to host, making sure
there's one single slash as path separator.

Removes an owner permission check before rendering the visibility
select radio inputs as non-admins will not have permission.

Ensures all users creating a group can select its visibility.

In EE, there is need to call `merge_requests_for_source_branch`
before calling CE's `refresh_merge_requests,
in order to obtain the old diffs.

However that requires `@push`,
initialized inside CE's refresh_merge_requests.

However it can't be set early in EE, or static analysis would fail
because use of instance variables in module is discouraged.
So @push is set in execute instead.