We perform a ton of expensive setup in this spec, via both `before` and
`let!`. When we use `skip` inside an `it` block, rather than skipping
the block entirely via `xit`, we still perform this expensive setup,
only to do absolutely nothing with it, resulting in wasted time.
Minutes, in this case.

Further, these specs have been sitting in our test suite for about seven
months now, so the likelihood of them being addressed soon seems low.

Since we don't support nested groups on MySQL, raise an error
explaining that on import instead of trying anyway.

For some old merge requests, we don't have enough information to figure out the
old blob and the new blob for the file. This means that we can't highlight the
diff correctly, but we can still display it without highlighting.

Closes #35994

Users of project mirrors would see that the number of branches did not
match the number in the branch dropdown because remote branches were
counted when Rugged was in use. With Gitaly, only local branches
are counted.

Closes #36934

Support simple string LDAP attribute specifications, and search for name rather than username attributes

Every project page displays a navigation menu that in turn displays the
number of open issues and merge requests. This means that for every
project page we run two COUNT(*) queries, each taking up roughly 30
milliseconds on GitLab.com. By caching these numbers and refreshing them
whenever necessary we can reduce loading times of all these pages by up
to roughly 60 milliseconds.

The number of open issues does not include confidential issues. This is
a trade-off to keep the code simple and to ensure refreshing the data
only needs 2 COUNT(*) queries instead of 3. A downside is that if a
project only has 5 confidential issues the counter will be set to 0.

Because we now have 3 similar counting service classes the code
previously used in Projects::ForksCountService has mostly been moved to
Projects::CountService, which in turn is reused by the various service
classes.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/36622

- Allow imports into nested groups
- Make sure it sets the correct visibility level when creating new
  groups

While doing this, I moved the import into a testable class, that made
it easier to improve.

It was missing and expected it wouldn't hurt anyone

This changes the style of push events that remove tags or branches so
they don't display the commit details. This prevents displaying commit
details such as:

    000000 . --broken encoding

Instead we now simply display the header such as:

    Administrator deleted branch example-branch

This is displayed in the same style as events for newly created
branches/tags.

This commit also ensures that if no commit message is present we simply
don't display anything, instead of "--broken encoding".

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/36685
Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/36722

Add `:broken_storage` metadata to examples to disable this behavior only
when necessary.

Prevents these from failing on MySQL.

Closes #36811 and #36812.