refactor(client/ts): port a few small files

src/public/app/widgets/buttons/create_pane_button.ts

@@ -0,0 +1,14 @@
+import { t } from "../../services/i18n.js";
+import OnClickButtonWidget from "./onclick_button.js";
+
+export default class CreatePaneButton extends OnClickButtonWidget {
+    constructor() {
+        super();
+
+        this.icon("bx-dock-right")
+            .title(t("create_pane_button.create_new_split"))
+            .titlePlacement("bottom")
+            .onClick((widget) => widget.triggerCommand("openNewNoteSplit", { ntxId: widget.getClosestNtxId() }))
+            .class("icon-action");
+    }
+}