API to identify bundle resources (like images)

[ruspl-afed]

We have a discussion in PDE and it partially addresses the problem of identifying package resources (like images) inside Java code to establish PDE API control for them.

This issue was created to discuss a specific implementation proposal,
an excerpt from it is given here:

public record ImageIdentityRecord(BundleIdentity bundle, String path, String key) implements ImageIdentity {

	@Override
	public String id() {
		return bundle.symbolic() + ".image." + key; //$NON-NLS-1$
	}

	@Override
	public String url() {
		return "platform:/plugin/" + bundle.symbolic() + "/$nl$/" + path; //$NON-NLS-1$ //$NON-NLS-2$
	}

}

PR with details will follow shortly