Utility emotes should be enumerated to permit direct code access

For example, the emote :CQCard: <:CQCard:459492749176209448> is used in a lot of places when referring to credits on the bot. Every place that uses it, however, has to reuse the string <:CQCard:459492749176209448>. This also means that if the emote is deleted and recreated (or potentially modified, but I haven't tested this), all the references to it need to be updated.

It would be far better to have a global list of these emotes in data/emotes.py or somesuch, which would allow stuff like f'You received 1000{Emotes.CQCard}' instead of 'You received 1000<:CQCard:459492749176209448>'.