Fix duplicate check in note editor

Duplicate checking was broken. I'm not sure if it ever worked or if we broke it in a recent change.

The content of the Note was never being updated to reflect the content in the text boxes in the editor, so the dupe check was only ever running on old values. I made it update the relevant (first) field before a dupe check.

I also removed the runnable that ran the dupe check. I have no idea what it was trying to accomplish...