REST broker: Handle registration error if invalid Naming convension used

You are not allowed to create REST Service Instances with dots/periods in the name as in “Customer.K2.SolutionName” versus “CustomerK2SolutionName” is okay.

We had a case which is now closed but it would be nice if the product would warn us users about illegal characters cutting out some of this guesswork from customers.

... and please if we can update documenation in the meantime if the product update not possible.