These are not required because MySQL is not
supported anymore

This stopped working in GitLab 11.11 when we upgraded to Rails 5.1.
Rails 5 changed ActionController::Parameters to return an Object instead
of a Hash. The old behavior was deprecated in Rails 5 but finally
removed in Rails 5.1

Since the controller wasn't updated properly, the callback endpoint
quietly failed with the message, "Could not connect to FogBugz, check
your url".

To fix this, we need to call `to_h` on the `import_params` to access the
Hash. We also need to do this for the user map and permit specific keys.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/33530

This sets up all the basics for importing Phabricator tasks into
GitLab issues.

To import all tasks from a Phabricator instance into GitLab, we'll
import all of them into a new project that will have its repository
disabled.

The import is hooked into a regular ProjectImport setup, but similar
to the GitHub parallel importer takes care of all the imports itself.

In this iteration, we're importing each page of tasks in a separate
sidekiq job.

The first thing we do when requesting a new page of tasks is schedule
the next page to be imported. But to avoid deadlocks, we only allow a
single job per worker type to run at the same time.

For now we're only importing basic Issue information, this should be
extended to richer information.

Adds frozen string to the following:

* spec/bin/**/*.rb
* spec/config/**/*.rb
* spec/controllers/**/*.rb

xref https://gitlab.com/gitlab-org/gitlab-ce/issues/59758

These are backend changes.
Use Vue for the import feature UI for "githubish"
providers (GitHub and Gitea).
Add "Go to project" button after a successful import.
Use CI-style status icons and improve spacing of the
table and its component.
Adds ETag polling to the github and gitea import
jobs endpoint.

To prevent an OAuth2 covert redirect vulnerability, this commit adds and
uses an alias for the GitHub and BitBucket OAuth2 callback URLs to the
following paths:

GitHub: /users/auth/-/import/github
Bitbucket: /users/auth/-/import/bitbucket

This allows admins to put a more restrictive callback URL in the OAuth2
configuration settings. Instead of https://example.com, admins can now use:

https://example.com/users/auth

It's possible but not trivial to change Devise and OmniAuth to use a
different prefix for callback URLs instead of /users/auth. For now,
aliasing the import URLs under the /users/auth namespace should suffice.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/56663

Bitbucket Server places personal projects in a namespace called
`~username`. This change allows those projects and also strips
them from the GitLab namespace.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/53419

The importer would display a 500 error page if you attempted to import
using a non-existent DNS entry. This commit rescues known network issues
and consolidates them into
BitbucketServer::Connection::ConnectionError`.  The previous error
handling in the paginator doesn't work because it returns a lazy
collection.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/56154