In the note applet, always paste without formatting by default. Add an action...

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:

{F7104991}

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

{F7104992}

Reviewers: davidedmundson, #plasma

Reviewed By: davidedmundson, #plasma

Subscribers: ngraham, plasma-devel

Tags: #plasma

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