Emojis should match when omitting underscores in the name

When searching for an emoji that contains underscores in its name, you must include the underscores, which makes it a harder to type and find what you're looking for.

When matching a substring against emojis, it should permit the omission of underscores, such that an emoji named :kett_pain: can be matched by both :kett_p and :kettp.

Stoat's emoji matching behaves this way image