Deny group transfer if group approval rules exist

What does this MR do and why?

In Allow only top level groups for ApprovalGroupRules (!144438 - merged) group approval rules were restricted to top level groups. As was discussed in #441436 (comment 1775585069)+ this MR enforces top level groups with approval rules cannot be made sub groups.

Deny group transfer if group approval rules exist

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Related to #441436