Add a biolink:CommonDataElementBundle to provide an ordered list of biolink:CommonDataElement

[gaurav]

Is your feature request related to a problem? Please describe.
biolink:CommonDataElement (CDE) is great (as proposed in #1096)! But CDEs are often administered as case report forms (CRFs), questionnaires, forms or bundles, and there isn't currently a way to model such an ordered group of CDEs in Biolink. This is a standard datatype: for example, the NIH CDE repository has an entry for the AUDIT Interview version, which consists of individual CDEs such as Patient Past Year Alcohol Consumption Frequency.

Describe the solution you'd like
It would be useful to have a new biolink:CommonDataElementBundle or similar class. I would propose we go with the definition from https://cde.nlm.nih.gov/guides:

• "A Form (sometimes known as a Bundle) is a set of questions or variables with specified sets of allowable responses that are bundled together and used as a set for particular research or clinical reasons. Bundles are indivisible and individual CDEs pulled from them are not considered valid."

I'm not sure about the best way of representing ordered lists in Biolink/LinkML, but we could maybe use biolink:has_member to connect a biolink:CommonDataElementBundle to its constituent biolink:CommonDataElement elements for now.

What working group (or team) did this request originate from?
Dug development team at RENCI

Additional context
Add any other context about the problem here.

Tag relevant members for discussion
@YaphetKG