N°6414 Separate SubFormField and Scalar fields

This will help to set methods as final, as SubFormField is often the sole one to have a real custom impl

sources/Form/Field/LinkedSetField.php

@@ -30,7 +30,7 @@ use ormLinkSet;
  * @author Guillaume Lajarige <guillaume.lajarige@combodo.com>
  * @since 2.3.0
  */
-class LinkedSetField extends Field
+class LinkedSetField extends AbstractSimpleField
 {
 	/** @var bool DEFAULT_INDIRECT */
 	const DEFAULT_INDIRECT = false;