- Remove Gitlab::ImportExport::ProjectCreator from GitlabProjectsImportService
- Override ::Projects::CreateService params

Currently we still need to run EnsureStageService within a transaction,
because when it runs within in a transaction we are going to stick to
the primary database when using database load balancing. Extracting this
out of the transaction makes it possible to hit into problems with
replication lag in pipeline commit status API, which can cause a lot of
trouble.

Validate project path in Gitlab import - 10.3 port

See merge request gitlab/gitlabhq!2268

(cherry picked from commit 94c82376d66fc80d46dd2d5eeb5bade408ec6a7e)

2b94a7c2 Validate project path in Gitlab import

We'd need to keep track of project full path otherwise directory tree created with hashed storage enabled cannot be usefully imported using the import rake task.

In this case the project will get the minimum between both
visibilities.

If that visibility is restricted, then a lower level will be picked.

If Unlinking a fork would fail somewhere after this, the LFS objects
might still be linked. Which would cause issues when trying to destroy
a project.

Comments from code review applied. Also switched forked_from_project and ForkedProjectLinks to ForkNetworkMember

Fix https://gitlab.com/gitlab-org/gitlab-ce/issues/38962