GroupSet validation is missing valid cases

[scalbertm]

Empty group name

In the last branch, GroupSet cannot be empty but there is no issue with a set named {id}.

Rule and GroupSetEditor validation should add case groupSet === "" && type === SetType.PREFIX
Adding both PREFIX and SUFFIX has no reason since they would undistinguishable

groupSetEditor

GroupSetEditor does not allow to have the same group name for a PREFIX and a SUFFIX (while the rest of the system allows it)