Transition new blocks from the mempool onto the blockchain.

Chime on new blocks.
fixes #47
fixes #84

frontend/src/app/interfaces/electrs.interface.ts

@@ -89,10 +89,13 @@ export interface Block {
   merkle_root: string;
   previousblockhash: string;
 
+  // Custom properties
   medianFee?: number;
   feeRange?: number[];
   reward?: number;
   coinbaseTx?: Transaction;
+  matchRate: number;
+  stage: number;
 }
 
 export interface Address {