Annotation processor support for generating reflect-config.json

[gayanper]

When working with plain java projects which doesn't use popular frameworks like spring, micronaught, the support for generating reflect-config.json files automatically for knowns project components such as records which are used as part of REST endpoint polos will not have the required reflection metadata to work with libraries like Jackson.

The agent doesn't generate these metadata either, so it would be nice to explicitly mark such component so that as part of the built the reflection metadata can be generated.

Describe the solution you'd like
One possible solution is to introduce compile only annotations to annotates type, constructors, fields, method etc. A annotation processor that is part of the gradle and maven plugins can generate required metadata. One such initiative can be found at https://github.com/mageddo-projects/annotation-processing-tools/tree/master/reflection-config-generator

But support such feature from the graalvm it self would be much better and also could be kept updated with latest changes happening in the graalvm project.

Describe alternatives you've considered
Using https://github.com/mageddo-projects/annotation-processing-tools/tree/master/reflection-config-generator