NOSTRGRAM UI UPDATE

Added some UI nice-to-haves that have been requested by folks. They certainly make things more polished.

* Clicking outside of any pop-up (dialog) window now closes the window (the escape key also closes most dialog windows)

* Feeds now fade in rather than just popping in when you change feed.

* New notes now enter the feed from left-to-right Round Robin style across the first row of notes (if viewing in multi-column mode)

* Any time something is copied to the clipboard (pubkey, note id, LN address etc) a subtle message is shown and fades out rather than a pop-up message box you have to close out of