Feat 193 ro injections

[mekhlakapoor]

closes #193

• creates container classes for RO injection info and Viral Info
• If RO injection is requested, maps to RetroOrbitalInjection model
• Uses prep lot id to extract and integrate viral info from TARS
• Adds unit test examples
• LAS has 3 options for injection eye: "left", "right", or either...the "either" option is being mapped to None

Notes:

• The LAS sharepoint list contains a good amount of viral material (but it's not standardized) so for now, TARS data overwrites injectable material info. In the future, we could refactor to map LAS's viral info instead of defaulting to overwrite (will be useful in the case that TARS response is empty).