feat: Add full Java module descriptors

[aalmiray]

Fixes #555

The following modules have been left as automatic

• restful-ws
• spring
• rocketmq

Because of the following issues:

Execution add-module-infos of goal org.moditect:moditect-maven-plugin:1.0.0.Final:add-module-info failed: Module java.xml.bind not found, required by java.ws.rs 

Error: Module rocketmq.client.java contains package javax.annotation, module annotations.api exports package javax.annotation to rocketmq.client.java 

Error: Modules java.annotation and jsr305 export package javax.annotation to module spring.webmvc 

[aalmiray]

ModiTect requires Java9+ to run. The build has been configured to keep producing Java 8 bytecode.
Build workflows can no longer be tested with Java 8. Added Java 21 as additional test target.