Describe the PR

Don't override "finalName" anymore. This however changes the filenames of the generated binary distribution files.

This fixes the following warnings and make sure, we can build PMD when overriding these properties won't be possible anymore:

[INFO] --- assembly:3.4.2:single (build-bin-dist) @ pmd-dist ---
[WARNING] Parameter 'finalName' is read-only, must not be used in configuration
[INFO] Reading assembly descriptor: src/main/resources/assemblies/pmd-bin.xml
[INFO] Building zip: /home/runner/work/pmd/pmd/pmd-dist/target/pmd-bin-7.0.0-SNAPSHOT.zip
[INFO] 
[INFO] --- assembly:3.4.2:single (build-src-dist) @ pmd-dist ---
[WARNING] Parameter 'finalName' is read-only, must not be used in configuration
[INFO] Reading assembly descriptor: src/main/resources/assemblies/pmd-src.xml
[INFO] Building zip: /home/runner/work/pmd/pmd/pmd-dist/target/pmd-src-7.0.0-SNAPSHOT.zip

Note: this is a 💥 breaking change: As the filename is changed, you might need to update your download/extract scripts.

Therefore, this change impacts also pmd-github-action and the landing page pmd.github.io.

Note 2: I've changed the filename for the doc.zip the same way for consistency.

Note 3: The content inside the zip-files stays the same: We still provide a base directory called pmd-bin-<version>.

Ready?

• Added unit tests for fixed bug/feature
• Passing all unit tests
• Complete build ./mvnw clean verify passes (checked automatically by github actions)
• Added (in-code) documentation (if needed)