deleteGroup
Deletes a group by its unique ID.
This method allows you to delete a specific group identified by the given groupId. Upon success, the group is removed from the groups property.
If the groupId is null or empty, the method returns immediately,and the listener's onError method is triggered with an appropriate error message.
Parameters
groupId
The unique identifier of the group to delete. If null or empty, the method returns immediately, and the listener's onError method is called.
listener
An optional RainbowListener that will be notified with the result of the delete operation.