Make StringType implement ComparableType

Author: Wout Gevaert

src/Traits/StringTypeTrait.php

@@ -32,7 +32,7 @@
  */
 trait StringTypeTrait
 {
-    use PropertyTypeTrait;
+    use ComparableTypeTrait;
     use AliasableTrait;
 
     /**

src/Types/PropertyTypes/StringType.php

@@ -25,11 +25,12 @@
 use WikibaseSolutions\CypherDSL\EndsWith;
 use WikibaseSolutions\CypherDSL\Regex;
 use WikibaseSolutions\CypherDSL\StartsWith;
+use WikibaseSolutions\CypherDSL\Traits\ComparableTypeTrait;
 
 /**
  * Represents the type "string".
  */
-interface StringType extends PropertyType
+interface StringType extends ComparableType
 {
     /**
      * Check whether this expression the given expression.