Rewrite onboarding

[rainbowdashlabs]

Rewrite the setup/onboarding command to properly integrate all new features when unlocked. Additionally change some stuff to drop down menus where applicable and correctly enforce restrictions.

Steps:

1. Select language
2. Add thankwords
3. Define channels and categories
4. Create reputation roles
5. Define announcement settings
6. Offer to disable donor and receiver context for guilds that want a simple thanking channel
7. Offer different reputation modes
8. Allow to set a custom reputation emoji (Mention supporter perks)

Blocked by discord-jda/JDA#2809 and discord-jda/JDA#2828