[Internal] [Feature] Accommodate additional biosample metadata templates starting with wastewater

[kyleoconnell]

What is the Feature Related To? Please Provide a Description.

Place an ❌ in a Box that Best Matches the Feature's Importance:

• [] 1 - Most important (absolutely integral and will not use codebase at all without it)
• [] 2-4 - Moderate (still using codebase for other functions but is serving as a blocker for future use-cases)
• [] 5 - Least important (would like to see but there are no stringent expectations nor urgency for current/future use-cases) 

Any Additional Context or Information? Has There Been Any Progress Made So Far Towards this Request? Any Helpful Resources to Reference? Screenshots or Links?

[jessicarowell]

Custom metadata fields now get added as Attributes in the submission.xml file (based on the biosample.xsd