Update CQL URLs to link to CQL R2 (2.0)

[cmoesel]

Now that CQL 2.0 has been released, update all URLs to point to pages under https://cql.hl7.org/R2/. I also checked to confirm that older links to the CQL spec were still correct when moved to R2 and that the corresponding quotes had not changed (when applicable). I did not do this for all of the build.fhir.org links in the interval code because there were not any changes to the spec since that version of the CI build.

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.)
• [n/a] 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 check to run tests, lint, and prettier)
• [n/a] All dependent libraries are appropriately updated or have a corresponding PR related to this change

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 88.70%. Comparing base (779b541) to head (2465762).

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #375   +/-   ##
=======================================
  Coverage   88.70%   88.70%           
=======================================
  Files          59       59           
  Lines        4933     4933           
  Branches     1429     1429           
=======================================
  Hits         4376     4376           
  Misses        322      322           
  Partials      235      235           

☔ View full report in Codecov by Harness.
📢 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.