Replace invocation of `find` with Ruby code that matches old cached
files in a better, and safe way to avoid data-integrity issues.

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

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

Currently, even when searching for all authorized issues of *one* project, we run the
`Users#authorized_projects` query (which can be rather slow). This update checks if
we are handling issues of just one project and does the authorization check locally.
It does have the downside of basically repeating the logic of `Users#authorized_projects`
on `Project#authorized_for_user`.

This version of MySQL doesn't yet support 'LIMIT & IN/ALL/ANY/SOME
subquery'

Oh well.

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/5347#note_13198105

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/5347#note_13199055

So we no longer join anything, just find the latest pipeline
and load builds from there to avoid mixing builds.

Thanks Kamil for the help and tests.

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

Closes #19741

also added a test for checking this.

Handle videos in:
- MD preview in notes: commit, issue/MR, MR diff
- New notes in: commit, issue/MR, MR diff
- Persisted notes in: commit, issue/MR, MR diff
Signed-off-by: NRémy Coutable <remy@rymai.me>