[MNG-6829] Replace StringUtils#isEmpty(String) & #isNotEmpty(String) (#159)

Last batch of is(Not)Empty for https://issues.apache.org/jira/browse/MNG-6829
These are the smallest change sets, hence why I opened more at the same time.
After this we can target the next most often used method from the StringUtils classes.


Use this link to re-run the recipe: https://public.moderne.io/recipes/org.openrewrite.java.migrate.apache.commons.lang.IsNotEmptyToJdk?organizationId=QXBhY2hlIE1hdmVu

Co-authored-by: Moderne <team@moderne.io>
diff --git a/src/main/java/org/apache/maven/plugins/jlink/AbstractJLinkToolchainExecutor.java b/src/main/java/org/apache/maven/plugins/jlink/AbstractJLinkToolchainExecutor.java
index 3ebce69..f08406e 100644
--- a/src/main/java/org/apache/maven/plugins/jlink/AbstractJLinkToolchainExecutor.java
+++ b/src/main/java/org/apache/maven/plugins/jlink/AbstractJLinkToolchainExecutor.java
@@ -158,12 +158,12 @@
         {
             int exitCode = CommandLineUtils.executeCommandLine( cmd, out, err );
 
-            String output = ( StringUtils.isEmpty( out.getOutput() ) ? null : '\n' + out.getOutput().trim() );
+            String output = StringUtils.isEmpty( out.getOutput() ) ? null : '\n' + out.getOutput().trim();
 
             if ( exitCode != 0 )
             {
 
-                if ( StringUtils.isNotEmpty( output ) )
+                if ( output != null && !output.isEmpty() )
                 {
                     // Reconsider to use WARN / ERROR ?
                     //  getLog().error( output );
@@ -185,7 +185,7 @@
                 throw new MojoExecutionException( msg.toString() );
             }
 
-            if ( StringUtils.isNotEmpty( output ) )
+            if ( output != null && !output.isEmpty() )
             {
                 //getLog().info( output );
                 for ( String outputLine : output.split( "\n" ) )