Migrate VM projects to Maven (JDK 1.5 Target)

-   Created Maven POM files for `vm` (parent), `ByteCodeTranslator`, `JavaAPI`, and `tests`.
-   Configured parent POM to use `maven-compiler-plugin` with source/target 1.5 and ASM 5.0.3, strictly preserving legacy semantics.
-   Updated `vm/tests/pom.xml` to use source/target 1.8 for test execution (JUnit 5 support) while testing JDK 1.5 artifacts.
-   Added `maven-antrun-plugin` to `ByteCodeTranslator` and `JavaAPI` to copy generated JARs to the legacy `dist/` directory for backward compatibility with external scripts.
-   Updated `.github/workflows/pr.yml` to replace Ant build commands with Maven commands for VM projects and updated artifact paths to `target/`.
-   Updated `.github/workflows/parparvm-tests.yml` to run Maven from the `vm` directory (reactor root) to correctly resolve module dependencies.
-   Reverted test source modifications to ensure no Java source files are changed.

Author: google-labs-jules[bot]

.github/workflows/parparvm-tests.yml

@@ -35,7 +35,7 @@ jobs:
           sudo apt-get install -y clang
 
       - name: Run ParparVM JVM tests
-        working-directory: vm/tests
+        working-directory: vm
         run: mvn -B test
 
       - name: Publish ByteCodeTranslator quality previews