Convert unit tests to Swift Testing

[vishnuravi]

Convert unit tests to Swift Testing

Migrates unit tests which are currently in XCTest to Swift Testing (addresses issue #89)

Code of Conduct & Contributing Guidelines

By creating and submitting this pull request, you agree to follow our Code of Conduct and Contributing Guidelines:

• I agree to follow the Code of Conduct and Contributing Guidelines.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.22%. Comparing base (ad35779) to head (9c8515a).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #95      +/-   ##
==========================================
- Coverage   86.10%   85.22%   -0.87%     
==========================================
  Files          28       28              
  Lines         489      372     -117     
==========================================
- Hits          421      317     -104     
+ Misses         68       55      -13     

Files with missing lines	Coverage Δ
...ests/FHIRPathParserTests/FHIRPathParserTests.swift	100.00% <ø> (+1.57%)	⬆️
...esearchKitOnFHIRTests/FHIRToResearchKitTests.swift	100.00% <100.00%> (+3.51%)	⬆️
.../ResearchKitOnFHIRTests/NavigationRulesTests.swift	100.00% <ø> (ø)
...esearchKitOnFHIRTests/ResearchKitToFHIRTests.swift	100.00% <ø> (ø)

... and 4 files with indirect coverage changes

---

Continue to review full report in Codecov by Sentry.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update ad35779...9c8515a. Read the comment docs.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[PSchmiedmayer]

Looks good; seems like we need to adjust one more test for it to compile and see that all tests are still succeeding on the CI. Thank you for all the work here @vishnuravi 🚀

[PSchmiedmayer]

Looks good; happy to see this merged once all the CI is passing 🚀