Function webext_storage::sync::outgoing::record_uploaded

pub fn record_uploaded(
    tx: &Transaction<'_>, 
    items: &[SyncGuid], 
    signal: &dyn Interruptee
) -> Result<()>

Record the fact that items were uploaded. This updates the state of the local DB to reflect the state of the server we just updated. Note that this call is almost certainly going to be made in a different transaction than the transaction used in stage_outgoing(), and it will be called once per batch upload.