Emote Cog Feature: Support Converting Images to Emoji

[Exper1mental]

ClemBot can currently get emojis from other servers and add them to a given server's emoji list. However, it does not support using images or GIFs and making those emojis on the server. I propose adding this functionality so people can easily use ClemBot to add emojis rather than having to save the images to their computer and manually upload them to discord.