test_runner: fix line feed escaping in JUnit

[AlexCannonball]

Fixes #59593 (a part related to the XML failure:message attribute value)

Cause

In escapeAttribute line feed characters were simply removed, so multi-line messages were distorted in the report, like:

The value must be 01 !== 0

However, the original message is:

The value must be 0

1 !== 0

Solution motivation

https://www.w3.org/TR/WD-xml-970807#sec3.3.3

Character references and references to internal text entities must be expanded

Thus, the character reference 
 must be expanded by the XML report processor/application to the line feed character.

Changes

I used the decimal code 
 as a decimal one is already used in escapeComment.

/(&)(?!#\d{1,7};)/g in escapeContent prevents escaping & in decimal character references.

Updated the test snapshot.

Effect

-		<failure type="testCodeFailure" message="Expected values to be strictly equal:true !== false">
+		<failure type="testCodeFailure" message="Expected values to be strictly equal:&#10;&#10;true !== false">

Testing

Additional details

I haven't removed testcase:failure as it's submitted via #59685

[nodejs-github-bot]

Review requested:

• @nodejs/test_runner

[codecov]

Codecov Report

❌ Patch coverage is 66.66667% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 88.57%. Comparing base (a520a39) to head (60c9808).
⚠️ Report is 35 commits behind head on main.

Files with missing lines	Patch %	Lines
lib/internal/test_runner/reporter/junit.js	66.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #60274      +/-   ##
==========================================
+ Coverage   88.56%   88.57%   +0.01%     
==========================================
  Files         704      704              
  Lines      208323   208323              
  Branches    40033    40039       +6     
==========================================
+ Hits       184501   184531      +30     
+ Misses      15854    15806      -48     
- Partials     7968     7986      +18     

Files with missing lines	Coverage Δ
lib/internal/test_runner/reporter/junit.js	94.47% <66.66%> (ø)

... and 33 files with indirect coverage changes

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[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/69818/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/69821/