Add maven wrapper and utf-8 standard encoding

[jannickherrmann]

Motivation

To ensure platform independence for Maven builds and to align with best practices for encoding standards.

Relates to: #205

What

Added Maven wrapper and set UTF-8 as default encoding.

Why

To make the build process more consistent across different platforms and to avoid encoding-related issues.

How

• Added Maven wrapper files (mvnw, mvnw.cmd, .mvn/wrapper/)
• Configured Maven to use UTF-8 encoding by default (<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> in pom.xml)

Verification Steps

1. Clone the repository.
2. Navigate to the project directory.
3. Verify that the Maven wrapper files (mvnw, mvnw.cmd) are present.
4. Open pom.xml and confirm <project.build.sourceEncoding> is set to UTF-8.
5. Run a build using the Maven wrapper (./mvnw clean install) and ensure the build completes successfully on different platforms (Windows, macOS, Linux) and no warning appeared for source encodig.

Checklist:

• Code has been tested locally by PR requester
• Changes have been successfully verified by another team member

Progress

• Finished task

Additional Notes

No additional notes.

[pb82]

@jannickherrmann thanks, I can confirm that the wrapper works (after marking the script as executable)

[alexted]

@pb82 could you pay attention to this enhancement?