In the note applet, always paste without formatting by default. Add an action to paste preserving formatting in the contextual menu.

Summary:
It frequently happens to me that formatting is preserved when pasting into the note, making the note a bit confusing. I added a button to remove formatting from the pasted text so that I can apply a different one with the other buttons. For example this is what I get when pasting from konsole:

but I'd personally prefer to be able to do something like this, in this specific case:

Reviewers: davidedmundson, Plasma

Reviewed By: davidedmundson, Plasma

Subscribers: ngraham, plasma-devel

Tags: Plasma

Differential Revision: https://phabricator.kde.org/D22774