message_edit: Show typing indicator for message editing.

This commit adds typing indicators for message editing in stream
as well as in dm, if the send typing notification
for corresponding is enabled.

Based on earlier work in #28585.

Co-authored-by: Rohan Gudimetla <rohan.gudimetla07@gmail.com>

Fixes #25719.

tools/check-schemas

@@ -61,6 +61,13 @@ def get_event_checker(event: dict[str, Any]) -> Callable[[str, dict[str, Any]],
     # Start by grabbing the event type.
     name = event["type"]
 
+    # This is a temporary workaround until a proper fix is implemented.
+    if name == "typing_edit_message":
+        if event["recipient"]["type"] == "channel":
+            name = "typing_edit_channel_message"
+        else:
+            name = "typing_edit_direct_message"
+
     # Handle things like AttachmentRemoveEvent
     if "op" in event:
         name += "_" + event["op"].title()