feat: implement forum helpers (#1087)

* feat: helpers helpers helpers

* docs: helpers helpers helpers

* Update error.py

Author: EepyElvyra

interactions/api/error.py

@@ -91,6 +91,7 @@ def lookup(code: int) -> str:
             11: "Error creating your command.",
             12: "Invalid set of arguments specified.",
             13: "No HTTPClient set!",
+            14: "Fatal conflict between object and attempted action.",
             # HTTP errors
             400: "Bad Request. The request was improperly formatted, or the server couldn't understand it.",
             401: "Not authorized. Double check your token to see if it's valid.",

interactions/api/http/channel.py

@@ -368,7 +368,7 @@ async def edit_tag(
             Route("PUT", f"/channels/{channel_id}/tags/{tag_id}"), json=_dct
         )
 
-    async def delete_tag(self, channel_id: int, tag_id: int) -> dict:
+    async def delete_tag(self, channel_id: int, tag_id: int) -> None:  # wha?
         """
         Delete a forum tag.
 

interactions/api/http/thread.py

@@ -228,7 +228,7 @@ async def create_thread_in_forum(
             payload["applied_tags"] = applied_tags
 
         data = None
-        if files is not MISSING and len(files) > 0:
+        if files is not MISSING and files and len(files) > 0:  # edge case `None`
 
             data = MultipartWriter("form-data")
             part = data.append_json(payload)