Editors: Added lexical editor for testing

Started basic playground for testing lexical as a new WYSIWYG editor.
Moved out tinymce to be under wysiwyg-tinymce instead so lexical is the
default, but TinyMce code remains.

resources/js/wysiwyg-tinymce/plugins-imagemanager.js

@@ -0,0 +1,29 @@
+/**
+ * @param {Editor} editor
+ */
+function register(editor) {
+    // Custom Image picker button
+    editor.ui.registry.addButton('imagemanager-insert', {
+        title: 'Insert image',
+        icon: 'image',
+        tooltip: 'Insert image',
+        onAction() {
+            /** @type {ImageManager} * */
+            const imageManager = window.$components.first('image-manager');
+            imageManager.show(image => {
+                const imageUrl = image.thumbs?.display || image.url;
+                let html = `<a href="${image.url}" target="_blank">`;
+                html += `<img src="${imageUrl}" alt="${image.name}">`;
+                html += '</a>';
+                editor.execCommand('mceInsertContent', false, html);
+            }, 'gallery');
+        },
+    });
+}
+
+/**
+ * @return {register}
+ */
+export function getPlugin() {
+    return register;
+}