20220707-1: Emoji Update

This update adds support for server emojis, including the following REST routes:

• GET /custom/emoji/<id>: Get an existing emoji
• PUT /custom/emoji/<id>: Create a new emoji (uses Autumn id)
• DELETE /custom/emoji/<id>: Delete an emoji
• GET /server/<id>/emojis: Fetch all emoji in a server

It adds a new permission ManageCustomisation with value 8.

It includes a new field in the Ready payload: emojis?: Emoji[].

It adds two new events:

• EmojiCreate(Emoji)
• EmojiDelete { id: String }