Create a RoleStory class or module

[crawfoal]

• hold information about the role story models and tables (basically all of the role story and role name related stuff that is currently in the Employment model)
• have a method for_user that behaves like an ActiveRecord scope, returning all role stories for a particular user (something like SetterStory.where(user: user).or(ManagerStory.where(user: user) only with metaprogramming so that all types of role stories are handled; maybe define a for_user method for each role story model in the Employable concern

Might be tempting to call it RoleStories because it contains information about all of the role story models, however if we call it RoleStory, then calls to the method above will look kind of like regular ActiveRecord stuff.