Discussions are now done asynchronously via the `IssuesController#discussions`
endpoint, so this should no longer be needed. This was taking 32% of the load
time for GitLab CE issue 1.

Closes #38034

In #37955,we see that the profile had a number of N+1 queries from repeated
access to `cross_reference_not_visible_for?`. This was optimized in previous
versions of GitLab by rendering all notes at once, counting the number of
visible references, and then using that number to check whether a system note
should be fully redacted.

There was also another N+1 query calling `ProjectTeam#member?`, which did not
take advantage of an optimization in prepare_notes_for_rendering that would
preload the maximum access level per project.

Closes #37955

This makes it easier to reuse in EE.

this will remove the need make N queries (per-note) at the
cost of having to mark notes with an attribute

this opens up the possibility for other special roles for notes

This changes the issue and MR index pages so the pagination system
re-uses the output of the COUNT(*) query used to calculate the number of
rows per state (opened, closed, etc). This removes the need for an
additional COUNT(*) on both pages.

Fix https://gitlab.com/gitlab-org/gitlab-ce/issues/34261

Its usage has been removed at 2fa22a07.

This reverts merge request !12633

Removed merge_request/issue state_event param parent and removed issuable_path helpers in favour of issuable_url helpers

This reverts merge request !12557

This reverts commit b07c0003, reversing
changes made to 2b97d76d.

We never want to skip the check, so that some actions did so was a mistake.

[ci skip]

Use the EnforcedStyleForMultiline: no_comma option.
Signed-off-by: Rémy Coutable <remy@rymai.me>

Use the EnforcedStyleForMultiline: no_comma option.
Signed-off-by: Rémy Coutable <remy@rymai.me>