HTML+JS+CSS UI work for searchable queue in Plush

> I've been trying to add a search box to the queue in Plush,
> like the History has. I haven't succeeded...

OK, I implemented the front-end UI changes to make the queue searchable! :mag: Search box adjusts as the window resizes and matches the history search UI.

@shypike, you'll need to tweak `_api_queue` to accept a search string filter param like `_api_history`, but i'm hoping that's easy for you now that the UI work's done (easy for me).

Changes tested in Chrome, Firefox, and Safari. Please LMK if there's an official SABnzbd browser suite that changes get tested against.