Fix mx unittest launch for configure tests - #13193

Summary

• Make the existing SVM unit-test launch configuration reusable.
• Apply it to SVM_TESTS so configure tests receive the required module exports and package opens.
• On current master, mx unittest ResourceConfigurationTest fails during JUnit discovery with an IllegalAccessError.

Related Issues

• Found while testing [GR-67556][Native Image] Preserve module-qualified resource bundles in Native Image metadata #13195.

Testing

• mx build --dependencies=SVM_TESTS --build-logs=silent
• mx unittest ResourceConfigurationTest (OK (3 tests))
• mx unittest com.oracle.svm.configure.test (OK (26 tests))
• mx checkstyle

Documentation

• No documentation updates are needed because this only changes the local unit-test launch configuration.

Contributor Checklist

• I have read the contribution guide.
• I have the right to contribute the submitted material under the project terms.
• I have updated tests and documentation where appropriate.
• If I used a coding assistant, I remain responsible for the entire contribution and have reviewed it accordingly.