feat(#834): Run 'unroll' In Parallel

[volodya-lombrozo]

In this PR I made UnrollMojo work in parallel. It significantly speeds up the entire goal.
For example, for phi-unphi integration test we got the following results:

Before (sequentially): 10s, 9s, 8s
After (with parallelism): 4s, 5s, 4s

Related to #834.

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PR-Codex overview

This PR focuses on enhancing the UnrollMojo and Unroller classes to improve the handling of PHI/UNPHI transformations, including logging improvements and adding new test classes. It also introduces a new dependency on Saxon-HE for XML transformations.

Detailed summary

• Added net.sf.saxon.TransformerFactoryImpl to the META-INF/services/javax.xml.transform.TransformerFactory.
• Introduced Saxon-HE dependency in pom.xml.
• Enhanced UnrollMojo with logging for transformation counts and execution time.
• Modified Unroller:
  • Changed constructor and method visibility from public to package-private.
  • Renamed unroll() method to return the count of unrolled files.
  • Added prepareThread() method for setting class loader properties.
• Created new classes A, B, C, and D in src/it/phi-unphi/src/main/java/org/eolang/hone/mess for testing purposes.

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[volodya-lombrozo]

@rultor merge

[rultor]

@rultor merge

@volodya-lombrozo OK, I'll try to merge now. You can check the progress of the merge here.

[rultor]

@rultor merge

@volodya-lombrozo Done! FYI, the full log is here (took me 11min).