Remove key-value store config

[mniip]

Remove key-value store config and replace it with proper database tables, preferably accessed by sqlalchemy.

• bot
  • bot.acl
  • bot.autoload
  • bot.commands
• plugins
  • plugins.appeals
  • plugins.automod
  • plugins.clopen
  • plugins.discord_log
  • plugins.factoids
  • plugins.keepvanity
  • plugins.log
  • plugins.modmail
  • plugins.persistence
  • plugins.phish
  • plugins.reminders
  • plugins.roleoverride
  • plugins.rolereactions
  • plugins.roles_dialog
  • plugins.roles_review
  • plugins.tickets
  • plugins.update
• plugins.activity