Raw textarea tag editor

[Zverik]

As hinted in #383: a raw tags editor mode inside the tags panel. Switched to a text area with a level0 representation of tags. The main tag goes first, the rest goes after, sorted by key.

[mnalis]

Is that intended in addition to current raw tag editor, or instead of it?

While former sounds great, the latter might be problematic (i.e. it is quite useful currently as it suggests tag names, and textarea probably wouldn't [if it behaves like any other textarea I've seen])

[Zverik]

I think of it as a toolbar button to switch views, not replacing anything.