Import forked repositories asynchronously to prevent large repositories from timing out
Preserve synchronous mode of adding a repository since some tasks (e.g. restore/check) require the former.
One side bug fix is that the ProjectCacheWorker
is also run, updating the repository size and commit numbers properly. Previously all the values were set to 0 when a project were forked.
- Closes #2388 (closed)
- Closes #2400 (closed)