display custom columns

[achen2401]

Part of #143
allow configurations of custom columns.
A config, FHIR_REST_EXTRA_PARAMS_LIST is added to allow specification of additional FHIR resource(s) needed for each patient.

For instance, tried, for DCW:
FHIR_REST_EXTRA_PARAMS_LIST = os.getenv("FHIR_REST_EXTRA_PARAMS_LIST", ["QuestionnaireResponse?_elements=resourceType,authored,subject&_sort=-authored"])

DASHBOARD_COLUMNS = [
        {
            "label": "MRN",
            "expr": "$.identifier[?(@.system=='https://hl7.org/mrn')].value"
        },
        {
            "label": "First Name",
            "expr": "$.name[0].given[0]",
        },
        {
            "label": "Last Name",
            "expr": "$.name[0].family",
        },
        {
            "label": "Birth Date",
            "expr": "$.birthDate",
        },
        {
            "label": "Last Assessed",
            "expr": "$.resources[?(@.resourceType=='QuestionnaireResponse')].authored",
             "sorting": False,
        },
    ]

Note, I tried _revinclude parameter to include additional resources, example. However, including such parameter returns a flat array of Patient resources and other resources, which I fear may mess up paging. Another issue with using _revinclude or _include parameters to query for additional FHIR resources for the patient is that one cannot seem to sort the additionally included resource(s). This is problematic if sorting the additional results is important (e.g. for DCW, to obtain last assessed date, one needs to sort the questionnaireResponses by authored date in descending order).

As a consequence, it seems the frontend needs to separately query for additional needed resources.

Also noting that sorting by Last Assessed doesn't seem feasible via FHIR query when combined with Patient resources and sorting by MRN will only show the ones that have relevant FHIR identifier (ones that don't won't show)

[mcjustin]

We decided to populate these fields, have them all sortable except for "last assessed", since that's very tricky.

[pbugni]

Good solution, thanks @achen2401

[ivan-c]

Looks great, thanks!