[lib][native] update useEditMessage return type

Summary:
ENG-8976;

SendEditMessageResult is used only in dispatchActionPromise, other than that we only care about success/failure.

With that change, we're able to use this hook also for DMs where SendEditMessageResult is not existing.

Test Plan: Editing still works

Reviewers: tomek, inka

Reviewed By: tomek

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D13186