Fix group selector options to not show parent group

[VladyslavLevinUA]

Description

Two issues fixed:

1. The group selector in the import screen could show the parent group as an option because of untracked dependency
2. Infinite loading that appears on group selection/clearing because of unhandled edge cases;

Checklist

Please ensure that each of these items has been addressed:

• I have tested these changes in my local environment
• I have added/modified tests as applicable to cover these changes
• (Atlassian contributors only) I have removed any Atlassian-internal changes including internal modules, references to internal tickets, and internal wiki links