Re-Add Capability to Use Layers for GD&T Visibility

[nmalik]

Pre - Creo functionality of Layers allowed for users to add GD&T / Annotations to a layer(s) then control the visibility.  Now per, CS95436, you must use the Show/Erase function for annotations.  The statement of "Works to product specification for Creo Parametric" is provided as a reason.  Not only is easier to toggle a layer but also easier to write into ModelCHECK standards.