Allow assessment domain model to capture all possible item responses

The assessment domain model currently only captures the correct response to an assessment item, but does not enable the capture of all items. This prevents the teacher (or other user) from seeing the range of possible choices the user was choosing from, which can be valuable – and sometimes critical – in the interpretation of results.

In particular, this functionality is important if the organization is attempting to capture survey-type data (e.g. likert responses) in the assessment model.

Note: while the practice of using the assessment domain for survey data is not necessarily recommended (as surveys often have different properties than assessments), community discussion (via the Assessment Work Group and TAG) have established that there may be cases where such capture is warranted (such as when a survey instrument is strongly tied to a SEL assessment of the student).

This capability is important to the SEL use cases as put forth by the AWG. See: https://techdocs.ed-fi.org/display/GOV/Assessment+Domain+-+Social+Emotional+Learning+Use+Case+-+Version+2-26-2019 (note this link may be volatile - search the use case resources of the AWG if it does not function).