Run sync in a loop

[tomasMizera]

Following https://github.com/MerginMaps/product/issues/83, let's introduce the sync loop

local_changes = true

while (local changes):
    pull_project()
    push_state = push_project()
    
    if push_state == success:
        local_changes = get_remaining_changes()
        clear retry counter
    else if push_state is error, but can be retried:
        sleep()
        increment retry counter
    else (push_state can not be retried || I have retried max times)
        break

Acceptance criteria:

• On "Somebody else is syncing" error, the app retries to sync
• Sync works as before