Retry failed download requests

[tomasMizera]

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

[alexd0793]

Tried on android and iOS. While downloading a bug project, i turned off the internet connection, and after turning back on, i saw in the logs the retries.
On windows not able yet to test, because of an issue with the app( i cannot go to see the logs). But victor is aware of it, once it's not an issue anymore i will close this testing