Bot API

This adds the following routes:

• POST /bots/create: Create a new bot.
• GET /bots/@me: Fetch all private bots.
• GET /bots/:bot: Fetch private bot information.
• PATCH /bots/:bot: Modify an existing bot.
• DELETE /bots/:bot: Delete a bot.
• GET /bots/:bot/invite: Fetch a snippet of public bot information.
• POST /bots/:bot/invite: Invite a bot to a server or group.

This also introduces two new schemas for Bot and PublicBot.

This modifies the user schema to add:

• User flags to indicate account suspension / deletion / ban.

• Optional bot object which indicates who owns the bot.

  Bot owner ID will always be public for transparency.