Better keyboard support

[h16nning]

• correct tab order when creating new cards (don't tab into controls toolbar)
• hotkey to trigger actions (e. g. "space" to trigger learn and "n" to add cards on DeckView) using mantine use-hotkeys

[eMerzh]

in that effort of better keyboard, it might be interesting to add hints about those shortcut, in badge, tooltip, or helpscreen or whatever

[h16nning]

I thought about using tooltips and an added helpscreen (maybe view specific) that can be brought up.