refactor: encapsulate prep and bump logic (#107)

Encapsulate logic for the following processes:
- Tx preparation
- fee bumping

So that they are out of the main retrying loop

Closes ENG-1084

Author: prestwich

bin/builder.rs

@@ -45,7 +45,6 @@ async fn main() -> eyre::Result<()> {
         config: config.clone(),
         constants,
         outbound_tx_channel: tx_channel,
-        host_provider: host_provider.clone(),
     };
 
     // Set up tx submission