Issue #3084528: Fixes several things: Moved checking for d8 drupal/drupal...

Issue #3084528: Fixes several things: Moved checking for d8 drupal/drupal further down the stack to avoid repeating that check everywhere.
Moved rebuilding of the provider includes into project_composer_process_release
Removed project_composer_process_release_project as it was an unnecessary go-between function.
Removed _project_composer_get_project_from_release_nid because we can use
project_release_get_release_project_nids