Capability annotation should be used by plugins to declare its capability

Example:

package io.jenkins.example.test;
@Capability("io.jenkins.example.test.ExampleTestReporter")
public class MyTestReporterAction extends AbstractTestResultAction {
    ...
}

BlueOcean API would report this capability when queried using its classes API as:

GET /rest/classes/io.jenkins.example.test.MyTestReporter

{
    "classes":["io.jenkins.example.test.ExampleTestReporter", "hudson.tasks.test.AbstractTestResultAction"]
}