Improve query relationship tests

[cmoesel]

This PR updates the model and query relationship tests to better reflect real relationship queries. It also tests behavior with empty secondary sources as described in FHIR-53144.

These changes include:

• Update simple model to add relationships from Conditions to Encounters
• Update simple model to add Medication record type
• Update tests to use relationship clauses that use real relationships
• Update tests to test relationships with empty secondary sources

Pull requests into cql-execution require the following.
Submitter and reviewer should ✔ when done.
For items that are not-applicable, mark "N/A" and ✔.

Submitter:

• This pull request describes why these changes were made
• Code diff has been done and been reviewed (it does not contain: additional white space, not applicable code changes, debug statements, etc.)
• Tests are included and test edge cases
• Tests have been run locally and pass
• Code coverage has not gone down and all code touched or added is covered.
• Code passes lint and prettier (hint: use npm run test:plus to run tests, lint, and prettier)
• All dependent libraries are appropriately updated or have a corresponding PR related to this change
• cql4browsers.js built with npm run build:browserify if source changed.

Reviewer:

Name:

• Code is maintainable and reusable, reuses existing code and infrastructure where appropriate, and accomplishes the task’s purpose
• The tests appropriately test the new code, including edge cases
• You have tried to break the code

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 87.55%. Comparing base (89ff93b) to head (5dccb52).

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #354   +/-   ##
=======================================
  Coverage   87.55%   87.55%           
=======================================
  Files          52       52           
  Lines        4596     4596           
  Branches     1295     1295           
=======================================
  Hits         4024     4024           
  Misses        359      359           
  Partials      213      213           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[hossenlopp]

Good catch! This should help us avoid mistakes during future updates. I skipped running this through fqm-e since no changes in compiled output.