feat: 🍰 EPIC Groups

Created by: Tirokk

🍰 Pullrequest

EPIC for groups.

Issues

• relates #5059 (closed)

Todo

• do we want all the GQLs as functions for unity?
• remove <group-button /> from default layout or make it configurable
• merge at least #5543
• create release v2.0.0
  • merge the master the last time into here
• cleanup
  • remove automatic deployment for groups of this branch before merge, see #5552