[Suggestion] Rename item pattern

[JerePenguin]

Pattern that takes a string, and renames item in offhand.

[Twisted-Code]

At least part of this was implemented in dev. In 1.20, there will be a new pattern that takes Entity, String and renames the entity to the string. It works on items on the ground, and I think it also works on nametagable entities.
The only thing I'm not sure about is whether it works on Item Stack/Item/Mote iotas, but if those are implemented this can probably be closed as complete.