Also:
- Changes scopes from serializer to use boolean columns
- Fixes broken specs

Since we can regenerate `description_html` from the `description`, we
should not export it. This avoids some complexity when overriding the
description during an import/export where we would need to invalidate
this cached field.

Now we refresh the markdown cache after the import

This makes accessing LFS Objects for a project easier

  project.lfs_storage_project.lfs_objects`

becomes

  project.all_lfs_objects

This will make the refactor in
https://gitlab.com/gitlab-org/gitlab-ce/issues/39769 easier to deal
with.

Closes gitaly#1110

Closes #28857

Prior to this change, this method was called add_namespace, which broke
the CRUD convention and made it harder to grep for what I was looking
for. Given the change was a find and replace kind of fix, this was
changed without opening an issue and on another feature branch.

If more dynamic calls are made to add_namespace, these could've been
missed which might lead to incorrect bahaviour. However, going through
the commit log it seems thats not the case.

We only allow users that can merge the merge request to push to the
fork.

The query becomes a lot simpler if we can check the branch name as
well instead of having to load all branch names.

When an MR is created using `allow_maintainer_to_push`, we enable some
abilities while the MR is open.

This should allow every user with developer abilities on the target
project, to push to the source project.

Use the max of the `last_activity_at` and `last_repository_updated_at`
columns. The latter is updated only when a push happens, but the former is
updated whenever any activity (e.g. issue creation) happens.

Closes #27181

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Fix using wildcards in protected tags to expose protected variables

When a project uses fast-forward merging strategy user has
to rebase MRs to target branch before it can be merged.
Now user can do rebase in UI by clicking 'Rebase' button
instead of doing rebase locally.

This feature was already present in EE, this is only backport
of the feature to CE. Couple of changes:
* removed rebase license check
* renamed migration (changed timestamp)

Closes #40301