This reverts commit 5a586f36

This reverts merge request !3191

Closes #13805

There's no need to order queries used as sub-queries and doing so can
add potential overhead.

This ensures some other methods such as the "issues" method still work.

Previously this class would be given a project ID which was then used to
retrieve the corresponding Project object. However, in all cases the
Project object was already known as it was used to grab the ID to pass
to ProjectSearchResults. By just passing a Project instead we remove the
need for an extra query as well as the need for some other complexity
in this class.

This removes the need for plucking snippet IDs into memory.

Instead of plucking IDs this class now uses ActiveRecord::Relation
objects. Plucking IDs is problematic as searching for projects can lead
to a huge amount of IDs being loaded into memory only to be used as an
argument for another query (instead of just using a sub-query).

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/12944

Fixes #12652

This reverts commit c04e22fb, reversing
changes made to 0feab326.

Closes #13469

- Apply the RelativeLinkFilter filter to other formats, e.g.,
  reStructuredText so links from the Files view or the Project view work
- Remove the AsciidocPipeline pipeline

Fixes #3533.

- Add `avatar_url`, `description`, `git_ssh_url`, `git_http_url`,
  `path_with_namespace` and `default_branch` in `project` in push, issue,
  merge-request and note webhooks data
- Deprecate the `ssh_url` in favor of `git_ssh_url` and `http_url` in
  favor of `git_http_url` in `project` for push, issue, merge-request and
  note webhooks data
- Deprecate the `repository` key in push, issue, merge-request and
  note webhooks data, use `project` instead