huge refactor of plugin system

cmdlet/__init__.py

@@ -103,6 +103,17 @@ def _register_native_commands() -> None:
         pass
 
 
+def _register_plugin_commands() -> None:
+    try:
+        from ProviderCore.commands import register_plugin_commands
+    except Exception:
+        return
+    try:
+        register_plugin_commands(REGISTRY)
+    except Exception:
+        pass
+
+
 def ensure_cmdlet_modules_loaded(force: bool = False) -> None:
     global _MODULES_LOADED
 
@@ -115,4 +126,5 @@ def ensure_cmdlet_modules_loaded(force: bool = False) -> None:
     _load_root_modules()
     _load_helper_modules()
     _register_native_commands()
+    _register_plugin_commands()
     _MODULES_LOADED = True