fix media resolving on editor switch

When switching editors, the current ID needs to be passed to the Ajax
call or media resolving for relative links will fail.

action/ajax.php

@@ -143,7 +143,8 @@ public function switchEditors(Event $event)
         $event->preventDefault();
         $event->stopPropagation();
 
-        global $INPUT;
+        global $INPUT, $ID;
+        $ID = $INPUT->str('id');
 
         if ($INPUT->bool('getJSON')) {
             $text = $INPUT->str('data');

script.js

@@ -122,6 +122,7 @@ function toggleEditor() {
         call: 'plugin_prosemirror_switch_editors',
         data: window.proseMirrorIsActive ? $jsonField.val() : $textArea.val(),
         getJSON: window.proseMirrorIsActive ? '0' : '1',
+        id: JSINFO.id
     }).done(function handleSwitchEditorResponse(data) {
         if (window.proseMirrorIsActive) {
             showDefaultEditor(data.text);