Make available field retrieval be generated through an object

phpcs-errors:221 phpunit-status:successful phpstan-errors:677

inc/constants.php

@@ -15,6 +15,7 @@
 ];
 
 const AUTOLOAD_DIRS = [
+    __DIR__ . "/../classes",
     __DIR__ . "/../classes/MDTlLoader/src",
     __DIR__ . "/../classes/MD_STD",
     __DIR__ . "/../classes/MDAllowedValueSets/src",

public/csv.php

@@ -31,7 +31,8 @@
 }
 else $selectionActive = false;
 
-require __DIR__ . "/../values/availableFields.php";
+$fieldsGetter = new CsvxmlAvailableFields($lang);
+$availableFields = $fieldsGetter->getFields();
 
 $line1 = $line2 = $line3 = $line4 = [];
 

public/index.php

@@ -57,7 +57,8 @@
     </div>
 ';
 
-require __DIR__ . "/../values/availableFields.php";
+$fieldsGetter = new CsvxmlAvailableFields($lang);
+$availableFields = $fieldsGetter->getFields();
 
 $tooltips = [];
 foreach ($availableFields as $headline => $fields) {

public/index3.php

@@ -25,7 +25,8 @@
 
 // Get allowed values * $fieldNoMultiplicator
 $fieldNoMultiplicator = 10;
-require __DIR__ . "/../values/availableFields.php";
+$fieldsGetter = new CsvxmlAvailableFields($lang);
+$availableFields = $fieldsGetter->getFields();
 
 $allowed = $eventpart = $eventpartsure = $fieldsWithDependency = $fieldsWithAllowedValueSet = [];