When a merge request is created from email, use message body
as merge request description. If message body is empty then
merge request description is still created from the source
branch commit (if there is only single commit in the merge
request).

If message body is empty and there are multiple commits in
the source branch, then merge request description is left empty.

Closes #40968

On GitLab.com, InfluxSampler#sample_objects appears to take 1.2 s or so to
iterate through 1059 objects. This had led to delays of a couple hundred
milliseconds in processing in the main thread. Remove this code since it's not
really being used.

Closes gitlab-com/infrastructure#3250

If the source import directory were different from the destination directory,
GitLab would first create a blank repository and then erroneously move the
original one into a subdirectory. Adding an import type prevents this the project
from being initialized in the first place. It was accidentally removed in
1f917cbd49.

Closes #40765

Prevent creating issues through API without having permissions

See merge request gitlab/gitlabhq!2225

(cherry picked from commit c298bbaa88883343dc9cbbb6abec0808fb3b546c)

915b97c5 Prevent creating issues through API without having permissions

[10.2] Ensure we expose group projects using GroupProjectsFinder

See merge request gitlab/gitlabhq!2234

(cherry picked from commit 072f8f2fd6ec794645375a16ca4ddc1cbeb76d7a)

a2240338 Ensure we expose group projects using GroupProjectsFinder

TableOfContents filter generates hrefs for each header in markdown,
if the header text consists from digits and redacted symbols only,
e.g. "123" or "1.0 then the auto-generated href has the same format
as issue references.

If the generated id contains only digits, then 'anchor-' prefix is
prepended to the id.

Closes #38473

Moving the check out of the general requests, makes sure we don't have
any slowdown in the regular requests.

To keep the process performing this checks small, the check is still
performed inside a unicorn. But that is called from a process running
on the same server.

Because the checks are now done outside normal request, we can have a
simpler failure strategy:

The check is now performed in the background every
`circuitbreaker_check_interval`. Failures are logged in redis. The
failures are reset when the check succeeds. Per check we will try
`circuitbreaker_access_retries` times within
`circuitbreaker_storage_timeout` seconds.

When the number of failures exceeds
`circuitbreaker_failure_count_threshold`, we will block access to the
storage.

After `failure_reset_time` of no checks, we will clear the stored
failures. This could happen when the process that performs the checks
is not running.

- handle unchanged empty lines in inline diff

Fix https://gitlab.com/gitlab-org/gitlab-ce/issues/40825

+ change string concatenation to help with GC pressure.
+ fix metric producing incompatible label sets

In EE we now allow individual users/groups to be set on POST, which required some refactoring.
See https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/3516

This also allows us to simplify the naming since we can make some
fetching methods private.

Use Class.new(StandardError) instead of custom extended error class. Bring back specified_dependencies?.