Add Clusters::KubernetesNamespace model

See merge request gitlab-org/gitlab-ce!22404

Move Project#rename_repo to a service class

See merge request gitlab-org/gitlab-ce!22419

This model will be used to persist into database Kubernetes properties,
such as namespace, service account name and service account token.

This moves the logic of Project#rename_repo and all methods _only_ used
by this method into a new service class: Projects::AfterRenameService.
By moving this code into a separate service class we can more easily
refactor it, and we also get rid of some RuboCop "disable" statements
automatically.

During the refactoring of this code, I removed most of the explicit
logging using Gitlab::AppLogger. The data that was logged would not be
useful when debugging renaming issues, as it does not add any value on
top of data provided by users.

I also removed a variety of comments that either mentioned something the
code does in literal form, or contained various grammatical errors.
Instead we now resort to more clearly named methods, removing the need
for code comments.

This method was chosen based on analysis in
https://gitlab.com/gitlab-org/release/framework/issues/28. In this issue
we determined this method has seen a total of 293 lines being changed in
it. We also noticed that RuboCop determined the ABC size
(https://www.softwarerenovation.com/ABCMetric.pdf) was too great.

Add RAW file format which is used to store security reports

Closes gitlab-ee#7996

See merge request gitlab-org/gitlab-ce!22365

Signed-off-by: Takuya Noguchi <takninnovationresearch@gmail.com>

- This introduces and uses `:raw` format for all legacy reports,
  the ones that do not have yet proper parsers on Backend
- Raw format is needed to make Frontend be able to parse reports,
  without the need of decompressing,
- This also extends fixtures to seed security reports with database,
  even though parser code is part of EE

This integration no longer works and does not appear to be supported.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/39697

Was introduced in the time that GitLab still used NFS, which is not
required anymore in most cases. By removing this, the API it calls will
return empty responses. This interface has to be removed in the next
major release, expected to be 12.0.