feat(mempool): implement commit_block method

crates/mempool/src/mempool.rs

@@ -110,10 +110,24 @@ impl Mempool {
     pub fn commit_block(
         &mut self,
         _block_number: u64,
-        _txs_in_block: &[TransactionHash],
-        _state_changes: HashMap<ContractAddress, AccountState>,
+        txs_in_block: &[TransactionHash],
+        state_changes: HashMap<ContractAddress, AccountState>,
     ) -> MempoolResult<()> {
-        todo!()
+        for tx_hash in txs_in_block {
+            self.tx_store.remove(tx_hash)?;
+            self.staging.remove(tx_hash)?;
+        }
+
+        for (contract_address, account_state) in state_changes {
+            self.state.insert(contract_address, account_state);
+        }
+
+        for tx_hash in self.staging.keys() {
+            let tx = self.tx_store.get(tx_hash)?.clone();
+            self.txs_queue.push(tx.into());
+        }
+
+        Ok(())
     }
 }