test: enable running individual independent functional test methods

- Some test methods in the functional test framework are independent
  and do not require any previous context or setup defined in `run_test`.
- This commit adds a new option for running these specific methods within a test file,
  allowing them to be executed individually without running the entire test suite.

- running test methods that require an argument or context will fail.

test/functional/test_framework/test_framework.py

@@ -129,7 +129,11 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
 
         try:
             self.setup()
-            self.run_test()
+            if self.options.test_methods:
+                self.run_test_methods()
+            else:
+                self.run_test()
+
         except JSONRPCException:
             self.log.exception("JSONRPC error")
             self.success = TestStatus.FAILED
@@ -155,6 +159,13 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
             exit_code = self.shutdown()
             sys.exit(exit_code)
 
+    def run_test_methods(self):
+        for method_name in self.options.test_methods:
+            self.log.info(f"Attempting to execute method: {method_name}")
+            method = getattr(self, method_name)
+            method()
+            self.log.info(f"Method '{method_name}' executed successfully.")
+
     def parse_args(self, test_file):
         previous_releases_path = os.getenv("PREVIOUS_RELEASES_DIR") or os.getcwd() + "/releases"
         parser = argparse.ArgumentParser(usage="%(prog)s [options]")
@@ -194,6 +205,8 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
                             help="use BIP324 v2 connections between all nodes by default")
         parser.add_argument("--v1transport", dest="v1transport", default=False, action="store_true",
                             help="Explicitly use v1 transport (can be used to overwrite global --v2transport option)")
+        parser.add_argument("--test_methods", dest="test_methods", nargs='*',
+                            help="Run specified test methods sequentially instead of the full test. Use only for methods that do not depend on any context set up in run_test or other methods.")
 
         self.add_options(parser)
         # Running TestShell in a Jupyter notebook causes an additional -f argument