Starting to separate the esplora client funcionality from business logic

Having a driver will allow us to start experimenting with transaction signing
more easily

side-node/src/bitcoin/driver.rs

@@ -0,0 +1,5 @@
+use crate::bitcoin;
+
+pub(crate) async fn run() {
+    bitcoin::clients::esplora::run().await.unwrap();
+}