Feat: incorporate EMX for Variant module

[davidruvolo51]

New Variant Classification Module

We would like to create a module for capturing variant information. Using the existing variants project as a starting point, create a module...

• where attributes follow the same naming format as the rest of the model. e.g., belongsTo..., reasonFor..., etc.
• that includes semantic tags for variant attributes
• and lookup tables relevant to the new variant table

Tasks

• convert existing model to yaml format
• harmonize attribute names
• add semantic tags
• create lookups

[davidruvolo51]

I'm closing this issue for now as this feature will be implemented in another way. At some point we may revisit this, but there aren't any plans to work on this.