Fix typo in application settings page

See merge request gitlab-org/gitlab-ce!18181

Resolve "ActiveRecord::RecordNotUnique: PG::UniqueViolation: ERROR:  duplicate key value violates unique constraint "index_ci_builds_meta..."

Closes #44922

See merge request gitlab-org/gitlab-ce!18155

Fix links to subdirectories of a directory with a plus character in its path

Closes #44967

See merge request gitlab-org/gitlab-ce!18172

Bulk deleting refs is handled by Gitaly by default

See merge request gitlab-org/gitlab-ce!18180

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

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

Redesign application settings to match project settings (part 6, final)

See merge request gitlab-org/gitlab-ce!18168

Has been stable for a while in production, so this endpoint grew out if
OPT_IN, the default state.

Part of https://gitlab.com/gitlab-org/gitaly/issues/526