@Resolution fields stay null: plugin.xml gets no <resolutions> #1230

Affected version

4.0.0-beta-3; the code is unchanged on master

Bug description

The annotation scanner collects @Resolution as a field annotation (MojoAnnotationsScanner.java:56), but nothing turns it into descriptor content, so plugin.xml gets no <resolutions> element. Maven core injects @Resolution fields only from that element (DefaultMavenPluginManager.java:616), so the field stays null and nothing reports an error.

Reproducer, built with maven-plugin-plugin 4.0.0-beta-3 and run with Maven 4.0.0-rc-7 on a project with one compile dependency; it prints paths=null:

@Mojo(name = "run")
public class ReproMojo implements org.apache.maven.api.plugin.Mojo {
    @Resolution(pathScope = "main-compile")
    List<Path> paths;

    public void execute() {
        System.out.println("paths=" + paths);
    }
}

Expected: one <resolution> per annotated field, with field, pathScope and requestType as defined by the resolutions element in plugin.mdo.