Investigate QuotaExceededError errors

[szimek]

When there's not much available storage on a device, transfers are terminated with QuotaExceededError. We're using temporary storage, which has more strict storage limits, but it was never a problem before when sending files even up to 1GB.

One thing would be to query and log storage size available to the app. At first it could simply show an error if the received file size exceeds available storage size. Later it could try to switch to persistent storage and ask user for permission, explaining why it's needed.