Split out the ratecontroller logic into functions

The original Lua code was duplicated per direction, making it more difficult to read and more prone to mistakes when changing things.

Start splitting this logic out into functions that are called per direction

src/main.rs

@@ -166,14 +166,12 @@ fn main() -> anyhow::Result<()> {
         ul_direction = StatsDirection::TX;
     }
 
-    let ratecontroller = Ratecontroller::new(
+    let mut ratecontroller = Ratecontroller::new(
         config.clone(),
         owd_baseline.clone(),
         owd_recent.clone(),
         reflector_peers_lock.clone(),
         reselect_sender.clone(),
-        dl_direction,
-        ul_direction,
     )?;
 
     debug!(