Align Java target to 8 and add CONTRIBUTING + Java 8 CI

[juancadavid]

Change maven-compiler-plugin release to 8 to ensure bytecode compatibility with Modelio 5.4.1 (Java 8).\n\nAdded CONTRIBUTING.md and a GitHub Actions workflow to build with Java 8 on push and PR.\n\nValidation: Built locally with 'mvn -B -DskipTests package' (BUILD SUCCESS).

[Copilot]

Pull Request Overview

This PR aligns the Java compilation target to Java 8 to ensure compatibility with Modelio 5.4.1, adds project documentation, and includes CI workflow for automated testing. The changes primarily involve regenerated source files with updated version numbers and identifiers, along with new project infrastructure.

• Updates Maven compiler configuration to target Java 8 bytecode
• Adds CONTRIBUTING.md with development setup instructions and GitHub Actions CI workflow
• Updates generated source files with new version numbers and regenerated UUIDs

Reviewed Changes

Copilot reviewed 33 out of 458 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
pom.xml	New Maven configuration targeting Java 8 with Modelio 5.4.1 compatibility
CONTRIBUTING.md	Development setup documentation for the project
.github/workflows/maven-java8.yml	CI workflow for building with Java 8
src/main/java/fr/softeam/toscadesigner/api/tosca/infrastructure/modelelement/*.java	Regenerated source files with updated version numbers and UUIDs
src/main/java/fr/softeam/toscadesigner/api/ToscaDesignerProxyFactory.java	Updated factory class with import fixes and class name corrections
src/main/conf/module.xml	Module configuration with binary version update

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