Syncing big projects in areas with low data coverage or often network issues can be challenging.

We want to implement a mechanism to retry requests after network error or different server errors.
Requests should be retried in case of network error and server 5xx http codes.

This ticket is only about project download, not about uploading chunks. Uploading is a bit more tricky and will be part of a different ticket.

Note: we already have sync retries in place, but this ticket applies to individual requests during sync.

Let's not retry more than 5 times for now (as a total in transaction).

Related issues #885, #1308