test_runner: escape carriage returns in snapshot values

[hanityx]

CR and CRLF from custom serializers such as String are written unescaped into
snapshot template literals and normalized to LF when the file is evaluated.
The default JSON serializer is unaffected.

For example, in JavaScript string notation:

Before saving: "a\r\nb"
After loading: "a\nb"

An unchanged value therefore fails comparison, while changing only the line
endings to LF can incorrectly pass.

Escape carriage returns in snapshot values and add CR/CRLF round-trip tests.

Existing snapshots containing unescaped CR values will still have those CRs
normalized to LF when evaluated until they are regenerated with --test-update-snapshots

[nodejs-github-bot]

Review requested:

• @nodejs/test_runner

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.22%. Comparing base (c1e2478) to head (d01b5a6).
⚠️ Report is 21 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #66040      +/-   ##
==========================================
- Coverage   90.23%   90.22%   -0.01%     
==========================================
  Files         785      789       +4     
  Lines      269670   270614     +944     
  Branches    51589    51798     +209     
==========================================
+ Hits       243325   244150     +825     
- Misses      16825    16933     +108     
- Partials     9520     9531      +11     

Files with missing lines	Coverage Δ
lib/internal/test_runner/snapshot.js	98.10% <100.00%> (+<0.01%)	⬆️

... and 56 files with indirect coverage changes

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