Feat: Implement PicoCLI interface

CityDoctorParent/CityDoctorValidation/src/main/java/de/hft/stuttgart/citydoctor2/CityDoctorValidationCLI.java

 package de.hft.stuttgart.citydoctor2;
 
-import java.util.concurrent.Callable;
 
+import de.hft.stuttgart.citydoctor2.check.ValidationConfiguration;
+import de.hft.stuttgart.citydoctor2.exceptions.CityDoctorWriteException;
+import de.hft.stuttgart.citydoctor2.parser.CityGmlParseException;
+import de.hft.stuttgart.citydoctor2.parser.InvalidGmlFileException;
+import picocli.CommandLine;
 import picocli.CommandLine.Command;
 import picocli.CommandLine.Option;
 
+import java.io.File;
+import java.io.IOException;
+
 @Command(name =  "citydoctor2", mixinStandardHelpOptions = true, description = "Validates CityGML files according to a provided validation-plan.")
-public class CityDoctorValidationCLI implements Callable<Integer> {
+public class CityDoctorValidationCLI implements Runnable {
 
     @Option(names = {"-i" , "--in" , "--input"},
             description = "Filepath of the CityGML file.",
@@ -15,23 +22,41 @@ public class CityDoctorValidationCLI implements Callable<Integer> {
 
     @Option(names = {"-c" , "--config" , "--configuration", "--plan"},
             description = "Filepath of the validation configuration .yml",
-            required = true)
-    private String config;
+            defaultValue = Option.NULL_VALUE)
+    private File config;
 
     @Option(names = {"-x" , "--xml" , "--xmlReport"},
-            description = "Create a XML validation report at target location")
+            description = "Create a XML validation report at target location",
+            defaultValue = Option.NULL_VALUE)
     private String xmlReport;
 
     @Option(names = {"-p" , "--pdf" , "--pdfReport"},
-            description = "Create a PDF validation report at target location")
+            description = "Create a PDF validation report at target location",
+            defaultValue = Option.NULL_VALUE)
     private String pdfReport;
 
     @Option(names = {"-o" , "--out" , "--output"},
-            description = "Create a validated copy of the CityGML input with QualityADE at target location.")
+            description = "Create a validated copy of the CityGML input with QualityADE at target location.",
+            defaultValue = Option.NULL_VALUE)
     private String output;
 
     @Override
-    public Integer call() throws Exception {
-        return 0;
+    public void run(){
+        try {
+            ValidationConfiguration valConfig;
+            if(config == null){
+                valConfig=ValidationConfiguration.loadStandardValidationConfig();
+            } else{
+                valConfig=ValidationConfiguration.loadValidationConfig(config.getAbsolutePath());
+            }
+            CityDoctorValidation.startValidationProcess(input, xmlReport, pdfReport, valConfig,output);
+        } catch (CityDoctorWriteException | CityGmlParseException | IOException | InvalidGmlFileException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    public static void main(String[] args) {
+        int exitCode = new CommandLine(new CityDoctorValidationCLI()).execute(args);
+        System.exit(exitCode);
     }
 }