LPS-35211 Add new method getRestrictedHandlers() so that they can report whether they have any restricted variables
LPS-35211 TemplateVariableGroup should be smart to ignore restricted variables when they are known
LPS-35211 Provide information about the restricted variables when necessary.

Right now this is a feature exclusive of Journal.
LPS-35211 Don't display the group name if it doesn't contain any variables

This wasn't happening before, but now it is due to the filtering of restricted variables