Enable cqf expressions to evaluate variables on questionnaire extensions

[ageryck]

Is your feature request related to a problem? Please describe.
The current problem is the inability to pass a saved date value to be used as a questionnaire date picker validation value i.e. using the dob as a minimum value to capture any patient-related services like immunization. This requires passing the already saved dob to used a min date on the questionnaire date picker. The cqf currently fails to evaluate the variable passed.

Describe the solution you'd like
Allow the cqf expression to access and evaluate expressions for parameters stored/passed in the launch context

Describe alternatives you've considered
prepopulating the questionnaire with the dob value and passing that as an express dob value

Additional context
The extension below currently works for max value validation, this feature should allow the use of the same extension or min value validation

{
              "url": "http://hl7.org/fhir/StructureDefinition/maxValue",
              "valueDate": {
                "extension": [
                  {
                    "url": "http://hl7.org/fhir/StructureDefinition/cqf-calculatedValue",
                    "valueExpression": {
                      "language": "text/fhirpath",
                      "expression": "today()"
                    }
                  }
                ]
              }
            }

Would you like to work on the issue?
Yes

[FikriMilano]

just to clarify.
we'll be passing declared variables, launchContexts, %resource, and other FHIRPath context variable when we evaluate the cqf-calculated-value for both min and max validator

[LZRS]

I will be working on this and would like to be assigned