phsl / new-api

- Introduced a new function `GetUserUsableGroupsCopy` to return a copy of user usable groups.
- Updated `GetUserUsableGroups` to utilize the new function for better encapsulation.
- Changed variable names from `UserUsableGroups` to `userUsableGroups` for consistency.
- Enhanced `GetUserUsableGroups` logic to ensure it returns a copy of the groups, preventing unintended modifications.