Remove Blockchain from wallet

Although somewhat convenient to have, coupling the Wallet with
the blockchain trait causes development friction and complexity.
What if sometimes the wallet is "offline" (no access to the blockchain)
but sometimes its online?
The only thing the Wallet needs the blockchain for is to sync.
But not all applications will even use the sync method and the sync
method doesn't require the full blockchain functionality.
So we instead pass the blockchain in when we want to sync.

- To further reduce the coupling with blockchain I removed the get_height call from `new` and just use the height of the
last sync in the database.
- I split up the blockchain trait a bit into subtraits.

src/blockchain/rpc.rs

@@ -33,7 +33,9 @@
 
 use crate::bitcoin::consensus::deserialize;
 use crate::bitcoin::{Address, Network, OutPoint, Transaction, TxOut, Txid};
-use crate::blockchain::{Blockchain, Capability, ConfigurableBlockchain, Progress};
+use crate::blockchain::{
+    Blockchain, Capability, ConfigurableBlockchain, GetHeight, Progress, WalletSync,
+};
 use crate::database::{BatchDatabase, DatabaseUtils};
 use crate::{BlockTime, Error, FeeRate, KeychainKind, LocalUtxo, TransactionDetails};
 use bitcoincore_rpc::json::{
@@ -139,7 +141,34 @@ impl Blockchain for RpcBlockchain {
         self.capabilities.clone()
     }
 
-    fn setup<D: BatchDatabase, P: 'static + Progress>(
+    fn get_tx(&self, txid: &Txid) -> Result<Option<Transaction>, Error> {
+        Ok(Some(self.client.get_raw_transaction(txid, None)?))
+    }
+
+    fn broadcast(&self, tx: &Transaction) -> Result<(), Error> {
+        Ok(self.client.send_raw_transaction(tx).map(|_| ())?)
+    }
+
+    fn estimate_fee(&self, target: usize) -> Result<FeeRate, Error> {
+        let sat_per_kb = self
+            .client
+            .estimate_smart_fee(target as u16, None)?
+            .fee_rate
+            .ok_or(Error::FeeRateUnavailable)?
+            .as_sat() as f64;
+
+        Ok(FeeRate::from_sat_per_vb((sat_per_kb / 1000f64) as f32))
+    }
+}
+
+impl GetHeight for RpcBlockchain {
+    fn get_height(&self) -> Result<u32, Error> {
+        Ok(self.client.get_blockchain_info().map(|i| i.blocks as u32)?)
+    }
+}
+
+impl WalletSync for RpcBlockchain {
+    fn wallet_setup<D: BatchDatabase, P: Progress>(
         &self,
         database: &mut D,
         progress_update: P,
@@ -187,10 +216,10 @@ impl Blockchain for RpcBlockchain {
             }
         }
 
-        self.sync(database, progress_update)
+        self.wallet_sync(database, progress_update)
     }
 
-    fn sync<D: BatchDatabase, P: 'static + Progress>(
+    fn wallet_sync<D: BatchDatabase, P: Progress>(
         &self,
         db: &mut D,
         _progress_update: P,
@@ -324,29 +353,6 @@ impl Blockchain for RpcBlockchain {
 
         Ok(())
     }
-
-    fn get_tx(&self, txid: &Txid) -> Result<Option<Transaction>, Error> {
-        Ok(Some(self.client.get_raw_transaction(txid, None)?))
-    }
-
-    fn broadcast(&self, tx: &Transaction) -> Result<(), Error> {
-        Ok(self.client.send_raw_transaction(tx).map(|_| ())?)
-    }
-
-    fn get_height(&self) -> Result<u32, Error> {
-        Ok(self.client.get_blockchain_info().map(|i| i.blocks as u32)?)
-    }
-
-    fn estimate_fee(&self, target: usize) -> Result<FeeRate, Error> {
-        let sat_per_kb = self
-            .client
-            .estimate_smart_fee(target as u16, None)?
-            .fee_rate
-            .ok_or(Error::FeeRateUnavailable)?
-            .as_sat() as f64;
-
-        Ok(FeeRate::from_sat_per_vb((sat_per_kb / 1000f64) as f32))
-    }
 }
 
 impl ConfigurableBlockchain for RpcBlockchain {