Overhaul reactions

[06000208]

The reactions stored in the config could do with some improvements

• There should be more of them, for a wider range of situations
• They should be used more consistently across the bot's commands
• Right now, the sandplate is taking advantage of how message.react() works, or more specifically, EmojiIdentifierResolvable. It doesn't matter if what you get is a unicode emoji or a snowflake, the same code works either way. But this method doesn't work if you want to use them in a message
• As such, it's likely that reactions in the config will be depreciated and a new object named emojis introduced

[06000208]

Configured custom emojis can start causing errors if the bot is logged in on an account without access to them, and #23 is relevant for implementing the necessary check.

[06000208]

At some point EmojiIdentifierResolvable was changed to handle emoji identifier strings (like <:name:id>) so this is much easier to implement