test: move sync_blocks and sync_mempool functions to test_framework.py

test/functional/wallet_balance.py

@@ -12,7 +12,6 @@ from test_framework.util import (
     assert_equal,
     assert_raises_rpc_error,
     connect_nodes,
-    sync_blocks,
 )
 
 
@@ -264,7 +263,7 @@ class WalletTest(BitcoinTestFramework):
         # Now confirm tx_orig
         self.restart_node(1, ['-persistmempool=0'])
         connect_nodes(self.nodes[0], 1)
-        sync_blocks(self.nodes)
+        self.sync_blocks()
         self.nodes[1].sendrawtransaction(tx_orig)
         self.nodes[1].generatetoaddress(1, ADDRESS_WATCHONLY)
         self.sync_all()