[SUREFIRE-2182] Log starter implementation on DEBUG level

For fork starter log the underlying configuration class name as well

maven-surefire-common/src/main/java/org/apache/maven/plugin/surefire/AbstractSurefireMojo.java

@@ -265,8 +265,10 @@ public abstract class AbstractSurefireMojo extends AbstractMojo implements Suref
 
     /**
      * Additional elements to be appended to the classpath.
+     * Each item must have the format
      *
      * @since 2.4
+     * @see <a href="https://docs.oracle.com/javase/8/docs/technotes/tools/windows/classpath.html">Java Class Path</a>
      */
     @Parameter(property = "maven.test.additionalClasspath")
     private String[] additionalClasspathElements;
@@ -1166,7 +1168,7 @@ private RunResult executeProvider(
                     (Properties) System.getProperties().clone();
             try {
                 createCopyAndReplaceForkNumPlaceholder(effectiveProperties, 1).copyToSystemProperties();
-
+                getConsoleLogger().debug("Using in-process starter");
                 InPluginVMSurefireStarter surefireStarter = createInprocessStarter(
                         provider,
                         classLoaderConfiguration,
@@ -1181,6 +1183,9 @@ private RunResult executeProvider(
         } else {
             ForkConfiguration forkConfiguration = createForkConfiguration(platform, resolvedJavaModularityResult);
             if (getConsoleLogger().isDebugEnabled()) {
+                getConsoleLogger()
+                        .debug("Using fork starter with configuration "
+                                + forkConfiguration.getClass().getName());
                 showMap(getEnvironmentVariables(), "environment variable");
                 showArray(getExcludedEnvironmentVariables(), "excluded environment variable");
             }