feat: Add rebrand CI/CD workflows to main branch

- Add 72 rebrand workflow files (polkadot→pezkuwi, substrate→bizinikiwi, cumulus→pezcumulus)
- Add GitHub actions, issue templates, and configs
- Removed unnecessary workflows (fork-sync, gitspiegel, upstream-tracker, sync-templates, backport)
- Renamed zombienet test files to match new naming convention

.github/scripts/cmd/_help.py

@@ -0,0 +1,26 @@
+import argparse
+
+"""
+
+Custom help action for argparse, it prints the help message for the main parser and all subparsers.
+
+"""
+
+
+class _HelpAction(argparse._HelpAction):
+    def __call__(self, parser, namespace, values, option_string=None):
+        parser.print_help()
+
+        # retrieve subparsers from parser
+        subparsers_actions = [
+            action for action in parser._actions
+            if isinstance(action, argparse._SubParsersAction)]
+        # there will probably only be one subparser_action,
+        # but better save than sorry
+        for subparsers_action in subparsers_actions:
+            # get all subparsers and print help
+            for choice, subparser in subparsers_action.choices.items():
+                print("\n### Command '{}'".format(choice))
+                print(subparser.format_help())
+
+        parser.exit()