Test using a master list of variables/definitions/requirements

[e-lo]

Test using a master list of variables/definitions/requirements and using references rather than redefining variables each time they are used.

• Easier to maintain
• Less error-prone
• Can document all variable definitions in a single place

Variables that are not "ids" should likely be defined in a separate list and incorporated by reference.

Variables that are "ids" of some kind should be defined in the table where they are the primary key.