#1644: fix pip GraalVM reflection and add automated validation test

[maybeec]

This PR fixes issue #1644 where pip was not working in the GraalVM native-image due to missing reflection configuration.

Changes

Core Fix

• reflect-config.json: Added missing reflection entries for:
  • PypiJsonObject (pip JSON response model)
  • GithubTag (GitHub API tag model)
  • GithubTags (GitHub API tags list model)

Automated Validation

• GraalVmReflectionConfigTest: New test class that:
  • Scans classpath for all JSON model classes (implementing JsonObject or JsonVersionItem)
  • Validates they're registered in reflect-config.json
  • Provides helpful error messages with copy-paste JSON snippets when missing entries detected
  • Uses vanilla Java (no external dependencies) for classpath scanning
  • Handles Windows path formatting correctly

Documentation Updates

• graalvm-build-guide.adoc: Added Section 4 "Reflection Configuration" covering:
  • Automated validation workflow
  • Adding new JSON API tools
  • Manual registration guide
  • Common error troubleshooting
• DoD.adoc: Added checklist requirement for JSON API tools to validate reflection config
• IDEasy-contribution-getting-started.adoc: Added "JSON Deserialization and GraalVM" subsection explaining the validation workflow

Testing

• mvn test -Dtest=GraalVmReflectionConfigTest passes ✅
• Test initially detected missing PypiJsonObject (TDD red phase)
• After adding reflection entries, test passes (TDD green phase)

DoD Checklist

• Code follows coding conventions (no star imports, proper JavaDoc, CamelCase)
• Added automated test (GraalVmReflectionConfigTest)
• Documentation updated (graalvm-build-guide, DoD, contribution guide)
• JSON model classes registered in reflect-config.json
• Test validates future JSON classes automatically

Closes #1644

[maybeec]

spottet by the test that GitHub tool might also not work, thus fixed it directly as well.

[coveralls]

Pull Request Test Coverage Report for Build 20231365932

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+0.09%) to 70.23%

---

Files with Coverage Reduction	New Missed Lines	%
com/devonfw/tools/ide/tool/ide/IdeToolCommandlet.java	1	78.33%

Totals
Change from base Build 20115895339:	0.09%
Covered Lines:	10155
Relevant Lines:	13893

---

💛 - Coveralls

[hohwille]

Thanks for your PR and the nice idea to prevent bugs like this again in the future via a JUnit test.
I created issue #1658 to rescue this wonderful idea. As described there the solution needs some further improvement.
In parallel I had already created a bugfix myself that follows our "old approach" that we always add an explicit hand-written JSON deserializer. That was PR #1656 that I decided to merge as hotfix for the bug #1644.
I therefore close this PR without merging but hope that we soon restore the valuable work and properly implement #1658 so we can remove the custom deserializers again that are rather boiler-plate code.