test_runner: escape carriage returns in snapshot values

[hanityx]

CR and CRLF line endings from custom serializers such as
String are normalized to LF when the snapshot file is evaluated:

Saved value:       "a\r\nb"
Loaded snapshot:   "a\nb"

An unchanged value therefore fails comparison, while an LF-only value can incorrectly pass.
Escape carriage returns in snapshot values and add CR/CRLF round-trip tests.

Regenerate affected snapshots 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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