fix: Add str arg support for modals in extensions, fix headers. (#533)

Author: FayeDel

interactions/client.py

@@ -1027,7 +1027,8 @@ def __new__(cls, client: Client, *args, **kwargs) -> "Extension":
                 func = client.modal(*args, **kwargs)(func)
 
                 modal = kwargs.get("modal") or args[0]
-                modal_name = f"modal_{modal.custom_id}"
+                _modal_id: str = modal.custom_id if isinstance(modal, Modal) else modal
+                modal_name = f"modal_{_modal_id}"
 
                 listeners = self._listeners.get(modal_name, [])
                 listeners.append(func)

interactions/client.pyi

@@ -107,11 +107,11 @@ def extension_command(
     default_permission: Optional[bool] = None,
 ): ...
 def extension_listener(name=None) -> Callable[..., Any]: ...
-def extension_component(component: Union[Button, SelectMenu]) -> Callable[..., Any]: ...
+def extension_component(component: Union[Button, SelectMenu, str]) -> Callable[..., Any]: ...
 def extension_autocomplete(
     name: str, command: Union[ApplicationCommand, int]
 ) -> Callable[..., Any]: ...
-def extension_modal(modal: Modal) -> Callable[..., Any]: ...
+def extension_modal(modal: Union[Modal, str]) -> Callable[..., Any]: ...
 def extension_message_command(
     *,
     name: Optional[str] = None,