Prettify the frontend code (#8648)

* Add Prettier global configs

* Format js/jsx/ts/tsx/less files

superset/assets/spec/javascripts/explore/components/QueryAndSaveBtns_spec.jsx

@@ -31,7 +31,9 @@ describe('QueryAndSaveButtons', () => {
 
   // It must render
   it('renders', () => {
-    expect(React.isValidElement(<QueryAndSaveButtons {...defaultProps} />)).toBe(true);
+    expect(
+      React.isValidElement(<QueryAndSaveButtons {...defaultProps} />),
+    ).toBe(true);
   });
 
   // Test the output