And add tests

Issues
https://gitlab.com/gitlab-org/gitlab-ce/issues/47149
https://gitlab.com/gitlab-org/gitlab-ce/issues/56014

Cached markdown version is composed both from global and local
markdown version. This allows admins to bump version locally when
needed (e.g. when external URL is changed).

Users downloading non-ASCII attachments would see garbled characters.
When used with object storage, AWS S3 would return an InvalidArgument
error: Header value cannot be represented using ISO-8859-1.

Per RFC 5987 and RFC 6266, Content-Disposition should be encoded
properly. This commit takes the Rails 6 implementation of
ActiveSuppport::Http::ContentDisposition
(https://github.com/rails/rails/pull/33829) and ports it here.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/47673

It was leaings confidential issue titles and MR titles to any users

Fix spec

Fix spec

Fix tests

This includes a set of APIs to manipulate container registry.
This includes also an ability to delete tags based on requested
criteria, like keep-last-n, matching-name, older-than.

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

Check if `X-Forwarded-For` is set before getting the IP of the request,
with this the real IP address of the runner is shown if it's behind a
proxy.

closes https://gitlab.com/gitlab-org/gitlab-ce/issues/53676

including refactoring, disabling sourcepos for pipelines that
don't need it, and minimizing spec changes by disabling
sourcepos when not testing for it explicitly.

This adds 'data-sourcepos' to tags, indicating which
line of markdown it came from.  Sets the stage for
intelligently manipulating specific lines of markdown.

In https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/15475/diffs, a
significant amount of work went into eliminating N+1 queries in the
/api/groups/:id/projects endpoint. We can reuse the
`Entities::Project.prepare_relation` call on the projects.

In a group with 2,573 projects on GitLab.com, this change significantly
improves performance:

* 18019 SQL queries down to 21
* Time spent in DB: 70 s down to 384 ms

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/49845

Currently if a project is inside a nested group and a user doesn't have
specific permissions for that group but does have permissions on a
parent group the `GET /projects/:id` API call will return the following
permissions:

```json
permissions: { project_access: null, group_access: null }
```

It could also happen that the group specific permissions are of lower
level than the ones the user has in parent groups. This patch makes it
so that the permission returned for `group_access` is the highest from
amongst the hierarchy, which is (ostensibly) the information that the
API user is interested in for that field.

For features the feature gates are sometimes projects, not groups or
users. For example for git object pools:
https://gitlab.com/gitlab-com/gl-infra/infrastructure/issues/5872

This commit allows for setting feature group gates based on projects, by its
path as that seems most convenient.

We introduced releases_page feature flag.
Given this feature is deemed stable, we should remove
this flag before 19th.

Modifies authorize! method to accept a third param, and then use it in
combination with 'add_cluster' policy to appropriately restrict adding
multiple clusters

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/56110

Refactor the epics/issues API specs to remove code duplication.

AuditEventService isn't equipped to handle logging of the destruction of
entities such as CI pipelines. It's a project-level event that operates
on a pipeline. The current log doesn't even indicate that the pipeline
is being destroyed.

This is a CE backport of
https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/9105.  We're
removing the auditing call because it breaks the EE implementation.

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