feat: Unified test-and-analyse (Polyglot Core)

[DerekRoberts]

Summary

We currently have fragmented actions for Node and Java analysis. We should consolidate these into a single, language-agnostic test-and-analyse core that leverages standard coverage formats.

The Proposal

Unify the 'Analysis' engine by decoupling the test execution from the report ingestion.

Key Features

1. Generic Coverage Ingestion: Support LCOV, JaCoCo, and Sonar-XML agnostically via a standard coverage_reports input.
2. Language-Aware Defaults: Use a language input to provide smart defaults for Node, Java, Python, etc., while allowing full commands overrides.
3. Single Quality Gate: One unified step for SonarCloud/Security analysis, regardless of source language.

Benefits

• Zero Fragmentation: Stop maintaining language-specific analysis clones.
• Scaling to New Languages: Adding Python (like Vexilon) or Go becomes a 5-minute config change rather than a new repo creation.