move group under non existing group

Created by: balcirakpeter

When I choose to move a group under another group and type a destination group name that does not exist, then the moving group is shifted as a top-level group.

To Reproduce Steps to reproduce the behavior:

1. Go to the list of groups in some Vo
2. Click on the move icon for some sub-group
3. Choose move under a group option
4. type some random string
5. Click on move
6. See that the group was moved as a top-level group

Expected behavior When I type a non-existing group name, It shouldn't be possible to click on the move button, or after clicking on it some error message should be displayed.