This change updates the classes used to render navigation tabs for
branches of a project.

New tabs are with compliant with Pajamas appearance.

Changelog: changed

We have issues with branches pagination
Let's disable the feature flag for standalone apps as well

Replaces the bootstrap modal for the delete branch button and
confirmation.

Changelog: added

This removes the aforementioned feature flag, enabling
the migrated dropdown component across all instances of GitLab

Updated the default branch name in the divergence graph

Gitaly keyset pagination returns a limited number of
branches. We can use it instead of fetching all
branches and then paginating them manually.

Projects::BranchesByModeService is introduced.
It uses Gitaly page-token pagination in order to
optimally fetch branches.
The drawback of the page-token pagination is that
it doesn't provide an option of going to the previous
page of the collection.
That's why we need to fall back to offset pagination
when previous page is requested.

Gitaly provides page-token pagination for branches instead of
offset pagination.

That means that we can't easily access a particular page of
the branches list without fetching all branches from Gitaly
and iterate them manually.

However, page-token pagination allows us to retrieve next bunch
of branches. We can use it in order to implement prev-next
pagination which should work more performant.

Where [a-m] is regex for all the folders in that directory starting
with that letter. This upgrades the buttons in those directories to use
the newer gitlab ui classes

Replaces the `btn-remove` classes with `btn-danger` and adds the
appropriate gitlab ui classes.

This commit also unifies layout structure
and remove no_container flag

This commit also unifies layout structure
and remove no_container flag

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/46139

Part of single codebase changes.

Part of single codebase changes.

Rename btn-new, btn-create and btn-save to btn-success
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Rename btn-new, btn-create and btn-save to btn-success
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

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

Fetch the merged branches at once, instead of checking it one
by one in the view. We don't cache this yet because this would
already much improve the performance.

EE for https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/14729