Implement keybinds in a way that can't potentially conflict with addons like Straight Rewards #11
Description
Follow-up on #10.
While there isn't actually a conflict with Straight Rewards due to the load order of Anki addons being alphabetic (P -> S), there should be a better way to sort out keybinds than by hooking reviewer_will_answer_card, which is sometimes used by addons which wish to read the answer chosen.