It's possible to create a group with no name

[flekschas]

Excepted: A group with an empty name shouldn't be allowed.

Observed: A group with an empty name is allowed.

After deleting the group with no name and trying to create it again it says

This name probably already exists - try a different name.

Create, deleting and re-creating a group with an actual name works fine

[ngehlenborg]

• create form validation check
• implement checks on backend and return error message from server on why creation failed