test: refactor rpc_signrawtransaction.py

rpc_signrawtransaction.py is split into rpc_signrawtransactionwithkey.py and wallet_signrawtransactionwithwallet.py.
rpc_signrawtransactionwithkey.py can be run with the wallet disabled.

test/functional/test_runner.py

@@ -181,8 +181,9 @@ BASE_SCRIPTS = [
     'rpc_whitelist.py',
     'feature_proxy.py',
     'feature_syscall_sandbox.py',
-    'rpc_signrawtransaction.py --legacy-wallet',
-    'rpc_signrawtransaction.py --descriptors',
+    'wallet_signrawtransactionwithwallet.py --legacy-wallet',
+    'wallet_signrawtransactionwithwallet.py --descriptors',
+    'rpc_signrawtransactionwithkey.py',
     'rpc_rawtransaction.py --legacy-wallet',
     'wallet_groups.py --legacy-wallet',
     'wallet_transactiontime_rescan.py --descriptors',