Migrate jobs from `storage_migrator` to
`hashed_storage:hashed_storage_migrator`.

This is the 1st step for moving Auto DevOps domain into cluster
settings, whether is project or group.

Related to https://gitlab.com/gitlab-org/gitlab-ce/issues/52363

Add migration and spec

commit 3cc12e1268a6865f524d8fab1804f018312fdf5a
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Tue Jan 8 19:34:31 2019 +0900

    Add changelog to this change

commit 5006fc96e38db514956a35f53ae8ee536548a2e9
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Tue Jan 8 19:32:56 2019 +0900

    Remove partial index from ci_builds artifact_file

    ok

    Update schema

commit 3c956bdc02b195bc67d0327bf3748a631ea5466d
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Mon Jan 7 21:41:27 2019 +0900

    Add frozen_string_literal: true

commit 8c827cd616890160e6e8908843403a6f20c03236
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Mon Jan 7 21:40:06 2019 +0900

    Set batch size 100

commit aeee559777d3bdeadfd2b9bb61d460f2dc1fa8a6
Author: Shinya Maeda <shinya@gitlab.com>
Date:   Fri Jan 4 18:33:05 2019 +0900

    Cleanup legacy artifact background migration

Retries in Sidekiq and in the remote mirror scheduler can cause repeated
attempts in quick succession if the sync fails. Each failure will then
send an e-mail to all project maintainers, which can spam users
unnecessarily.

Modify the logic to send one notification the first time the mirror
fails by setting `error_notification_sent` to `true` and reset the
flag after a successful sync.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/56222

These are data columns that store runtime configuration
of build needed to execute it on runner and within pipeline.

The definition of this data is that once used, and when no longer
needed (due to retry capability) they can be freely removed.

They use `jsonb` on PostgreSQL, and `text` on MySQL (due to lacking
support for json datatype on old enough version).

Fix coding style

Improve coding style

Decouple UPDATE and DELETE operations of asset links

Rename links_attributes to assets:links

Rename exposed param and updated spec

- Add Releases::Links model
- Expose it in release API
- Add integration tests

Many changes were also made to tests that expected this to default to
false.

This is useful to distinguish any other indexes on the same columns but
with different conditions and/or sorting.

This adds specific indexes to speed up the query mentioned in
https://gitlab.com/gitlab-org/gitlab-ce/issues/50763 and to avoid
statement timeouts.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/50763.

Adds a background migration that will ensure all projects that
are on legacy storage have a row in `project_repositories`.

This commit adds a name to each release, defaulting it to tag name,
keeps track of the SHA when a new release is created and tracks the
current user as release author.

When a project is forked, the new repository used to be a deep copy of everything
stored on disk by leveraging `git clone`. This works well, and makes isolation
between repository easy. However, the clone is at the start 100% the same as the
origin repository. And in the case of the objects in the object directory, this
is almost always going to be a lot of duplication.

Object Pools are a way to create a third repository that essentially only exists
for its 'objects' subdirectory. This third repository's object directory will be
set as alternate location for objects. This means that in the case an object is
missing in the local repository, git will look in another location. This other
location is the object pool repository.

When Git performs garbage collection, it's smart enough to check the
alternate location. When objects are duplicated, it will allow git to
throw one copy away. This copy is on the local repository, where to pool
remains as is.

These pools have an origin location, which for now will always be a
repository that itself is not a fork. When the root of a fork network is
forked by a user, the fork still clones the full repository. Async, the
pool repository will be created.

Either one of these processes can be done earlier than the other. To
handle this race condition, the Join ObjectPool operation is
idempotent. Given its idempotent, we can schedule it twice, with the
same effect.

To accommodate the holding of state two migrations have been added.
1. Added a state column to the pool_repositories column. This column is
managed by the state machine, allowing for hooks on transitions.
2. pool_repositories now has a source_project_id. This column in
convenient to have for multiple reasons: it has a unique index allowing
the database to handle race conditions when creating a new record. Also,
it's nice to know who the host is. As that's a short link to the fork
networks root.

Object pools are only available for public project, which use hashed
storage and when forking from the root of the fork network. (That is,
the project being forked from itself isn't a fork)

In this commit message I use both ObjectPool and Pool repositories,
which are alike, but different from each other. ObjectPool refers to
whatever is on the disk stored and managed by Gitaly. PoolRepository is
the record in the database.

Brings back 1e8f1de0 reverted in !23644

Closes #52342

See merge request gitlab-org/gitlab-ce!23436

This reverts commit 1e8f1de0, reversing
changes made to 62d97112.

This reverts commit d7291c64

This reverts commit c3d0f129

To separate the different kinds of repositories we have at GitLab this
table will be renamed to pool_repositories. A project can, for now at
least, be member of none, or one of these. The table will get additional
columns in a later merge request where more logic is implemented for the
model.

Further included is a small refactor of logic around hashing ids for the
disk_path, mainly to ensure a previous implementation is reusable.

The disk_path for the pool_repositories table no longer has a NOT NULL
constraint, but given the hashing of the ID requires the DB to assign
the record an ID, an after_create hook is used to update the value.

A related MR is:
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/23143, adding
tables for 'normal' repositories and wiki_repositories.

This approach caused many different problems as we tightened
the query execution timeout.