tests: log node JSON-RPC errors during test setup

Currently, if the node replies to any command with an error during
the test framework's setup(), we log the generic and not really useful
"Unexpected exception" from the BaseException catch, with no further
information.
This isn't helpful for diagnosing the issue. Fix it by explicitly handling
JSONRPCException and logging the response error message and http status
code.

test/functional/test_framework/test_framework.py

@@ -147,6 +147,9 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
         except subprocess.CalledProcessError as e:
             self.log.exception(f"Called Process failed with stdout='{e.stdout}'; stderr='{e.stderr}';")
             self.success = TestStatus.FAILED
+        except JSONRPCException as e:
+            self.log.exception(f"Failure during setup: error={e.error}, http_status={e.http_status}")
+            self.success = TestStatus.FAILED
         except BaseException:
             self.log.exception("Unexpected exception")
             self.success = TestStatus.FAILED