Add immunization measles workflow test

[delcroip]

Description

add test for measles plandefinition
fix the testing repository implementation by making search nullable (call with null in valueset expand cqframework/clinical-reasoning#365)

Alternative(s) considered
Have you considered any alternatives? And if so, why have you chosen the approach in this PR?

Type
Choose one: (Bug fix | Feature | Documentation | Testing | Code health | Builds | Releases | Other)

Screenshots (if applicable)

Checklist

• [x ] I have read and acknowledged the Code of conduct.
• I have read the Contributing page.
• I have signed the Google Individual CLA, or I am covered by my company's Corporate CLA.
• I have discussed my proposed solution with code owners in the linked issue(s) and we have agreed upon the general approach.
• I have run ./gradlew spotlessApply and ./gradlew spotlessCheck to check my code follows the style guide of this project.
• I have run ./gradlew check and ./gradlew connectedCheck to test my changes locally.
• I have built and run the demo app(s) to verify my change fixes the issue and/or does not break the demo app(s).

[jingtang10]

can you please give the pr a descriptive name @delcroip? thanks!

[jingtang10]

I think this needs gradle spotlessApply to format the code.

[jingtang10]

thanks @delcroip! so this also download the entire ig to the resource folder? in #2261 the ig is saved in sampledata/smart-imm and here they are saved in resources. do you think it's easy to unify?

[delcroip]

I will have a look into that but I will have to update the content because Jose and Bryn did lot on the measles IG

[delcroip]

Please close this one

[jingtang10]

thanks @delcroip!