DashboardSettings & PanelEdit: Use new PageToolbar (#30675)

* DashboardSettings & PanelEdit: Use new PageToolbar

* Update

* removed back button

public/app/core/components/BackButton/BackButton.tsx

@@ -1,23 +0,0 @@
-import React, { ButtonHTMLAttributes } from 'react';
-import { IconButton } from '@grafana/ui';
-import { selectors } from '@grafana/e2e-selectors';
-
-export interface Props extends ButtonHTMLAttributes<HTMLButtonElement> {
-  surface: 'dashboard' | 'panel' | 'header';
-}
-
-export const BackButton: React.FC<Props> = ({ surface, onClick }) => {
-  return (
-    <IconButton
-      name="arrow-left"
-      tooltip="Go back (Esc)"
-      tooltipPlacement="bottom"
-      size="xxl"
-      surface={surface}
-      aria-label={selectors.components.BackButton.backArrow}
-      onClick={onClick}
-    />
-  );
-};
-
-BackButton.displayName = 'BackButton';