[API] Fix URLs in the 'Link' header for 'GET /projects/:id/repository/contributors' when no value is passed for 'order_by' or 'sort'

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

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

There are 2 problems with this spec:

1. It checks for default visiblity level however there is not code in
controller to handle such default. Same check can be performed on model
directly.
2. It passes empty application_setting hash while controller requires
application_setting not to be empty by using `require` with `permit`

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

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

If form does not have import sources checkboxes we should not reset
import sources to empty. This fixes issue when import sources got reset
after user modifies unrelated settings section like GitLab pages

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

Closes #45326

Since !18150 abstract reference filter supports also `group`
as a resource parent (not only `project`). Some reference filters,
which inherit from abstract filter, depend on parent being `project`
when checking a reference.

This patch adds explicit check of parent class to the given filters.

Fixes gitaly#1126

Clients can now request the attributes from `$GIT_DIR/info/attributes`
through Gitaly. The Gitaly migration is described in gitlab-org/gitaly#1082.

The parser algorithm was implemented in a way it could handle both file
contents or a File handle, and both were already tested.

Other than that, using the boy scout rule, I've removed a class,
InfoAttributes, as it was delegating everything to the parser and
therefor wasn't really needed in my opinion.

This refactors the Markdown pipeline so it supports the rendering of
multiple documents that may belong to different projects. An example of
where this happens is when displaying the event feed of a group. In this
case we retrieve events for all projects in the group. Previously we
would group events per project and render these chunks separately, but
this would result in many SQL queries being executed. By extending the
Markdown pipeline to support this out of the box we can drastically
reduce the number of SQL queries.

To achieve this we introduce a new object to the pipeline:
Banzai::RenderContext. This object simply wraps two other objects: an
optional Project instance, and an optional User instance. On its own
this wouldn't be very helpful, but a RenderContext can also be used to
associate HTML documents with specific Project instances. This work is
done in Banzai::ObjectRenderer and allows us to reuse as many queries
(and results) as possible.

When a user is not logged in, we want to show the `New Issue` link so
he gets directed to the login flow first.

When a project is archived, we never want to show the link.