* migrate emojis
* add get emoji to s2s (federation) API
* add new emoji db + cache functions
* add shortcodeDomain lookup for emojis
* check existing emojis w/cache, not w/constraints
* go fmt
* add putEmoji func
* use new db emoji funcs instead of where
* remove emojistringstotags func
* add unique constraint back in
* fix up broken migration
* update index