Introduce quarkus-core-compatibility extension metadata

This introduces a `quarkus-core-compatibility` metadata in the extension YAML descriptor. It should serve as an indicator for core compatibilty for a given Quarkus version.
The format is `[major.minor,)`.

independent-projects/extension-maven-plugin/src/main/java/io/quarkus/maven/ExtensionDescriptorMojo.java

@@ -20,6 +20,7 @@
 import java.util.concurrent.atomic.AtomicReference;
 
 import org.apache.maven.artifact.Artifact;
+import org.apache.maven.artifact.versioning.DefaultArtifactVersion;
 import org.apache.maven.execution.MavenSession;
 import org.apache.maven.model.Scm;
 import org.apache.maven.plugin.AbstractMojo;
@@ -620,6 +621,11 @@ private void setBuiltWithQuarkusCoreVersion(ObjectNode extObject) throws MojoExe
  if (coreVersionLocator.coreVersion != null) {
  ObjectNode metadata = getMetadataNode(extObject);
  metadata.put("built-with-quarkus-core", coreVersionLocator.coreVersion);
+ if (!metadata.has("quarkus-core-compatibility")) {
+ DefaultArtifactVersion dav = new DefaultArtifactVersion(coreVersionLocator.coreVersion);
+ String compatibilityRange = "[" + dav.getMajorVersion() + "." + dav.getMinorVersion() + ",)";
+ metadata.put("quarkus-core-compatibility", compatibilityRange);
+ }
  } else if (!ignoreNotDetectedQuarkusCoreVersion) {
  throw new MojoExecutionException("Failed to determine the Quarkus core version used to build the extension");
  }