Fix failing tests

[katy-sadowski]

Fix failing tests on #464. Tests are failing because the DEATH measurePersonCompleteness check is now marked Yes in the updated threshold files, and as such the new sqlOnly output includes SQL queries for the DEATH check. To fix the failing tests the expected SQL queries needed to be updated, as did the expected number of inserted results table rows.

I ended up refactoring the SQL query output tests to use testthat snapshots instead of the previous approach of comparing to static SQL files, which made debugging failures hard/impossible. Snapshots allow us to view a nice diff of actual vs expected results when we run tests locally. I needed to upgrade to testthat edition 3 to access the snapshots feature, and as a result I also included a few other refactors related to the edition 3 upgrade.

[codecov]

Codecov Report

Merging #468 (1daf3c6) into develop (b89d4e8) will decrease coverage by 0.48%.
The diff coverage is 100.00%.

❗ Current head 1daf3c6 differs from pull request most recent head 765be21. Consider uploading reports for the commit 765be21 to get more accurate results

@@             Coverage Diff             @@
##           develop     #468      +/-   ##
===========================================
- Coverage    85.95%   85.47%   -0.48%     
===========================================
  Files           15       15              
  Lines          847      847              
===========================================
- Hits           728      724       -4     
- Misses         119      123       +4     

Impacted Files	Coverage Δ
R/evaluateThresholds.R	83.72% <100.00%> (ø)

... and 2 files with indirect coverage changes