!str #16484 #16392 Remove String identifier of junctions

* descriptive name can still be defined with OperationAttributes.name
* revisit all factory methods (apply/create) and implement and document
  them in a consistent manner

Refs #16484 
Refs #16392
it's so much duplication, don't you think users will find the "core" method?
I'll see if I can get the hang of scaladoc linking of overloaded methods, and thereby add a `see`