test: Turn util/test_runner into functional test

The moved portion can be reviewed via:

--color-moved=dimmed-zebra  --color-moved-ws=ignore-all-space

test/functional/test_runner.py

@@ -170,6 +170,7 @@ BASE_SCRIPTS = [
     'wallet_txn_doublespend.py --mineblock',
     'tool_bitcoin_chainstate.py',
     'tool_wallet.py',
+    'tool_utils.py',
     'tool_signet_miner.py',
     'wallet_txn_clone.py',
     'wallet_txn_clone.py --segwit',