Group export/import integration follow up - code cleanup

Overview

Once the group export/import is fully integrated and tested there will be a fair amount of redundant code. The same applies for newly introduced attributes to the project export/import.

Tasks

• Remove group migration code
• Remove import user from group members
• Remove other redundant code based on the following table
• Update README.md if needed

Migration features

Project and Group export/import | Congregate

✅ = supported ❌ = not supported

Main	Feature	Sub-feature	GitLab	Congregate
Group
	Badges		✅	✅ (to be removed)
	Members		✅	✅ (to be removed)
Project
	Members		✅	✅ (disabled)
	Pipeline schedules		✅	✅ (disabled)
	Protected Branches	Merge Access Levels, Push Access Levels, Unprotect Access Levels	✅	✅ (to be removed)
	Protected Environments	Deploy Access Levels	✅	✅ (to be removed)
	Badges		✅	✅ (update only - to be removed)
	CI variables		✅	✅ (to be removed)
	Avatars		✅	✅ (disabled)
	Awards		✅	✅ (to be removed)