fix(striker-ui): expose panelClasses

striker-ui/components/Panels/Panel.tsx

@@ -115,4 +115,6 @@ const Panel: FC<PanelProps> = ({
 
 Panel.defaultProps = PANEL_DEFAULT_PROPS;
 
+export { classes as panelClasses };
+
 export default Panel;

striker-ui/components/Panels/index.tsx

@@ -2,7 +2,7 @@ import ExpandablePanel from './ExpandablePanel';
 import InnerPanel from './InnerPanel';
 import InnerPanelBody from './InnerPanelBody';
 import InnerPanelHeader from './InnerPanelHeader';
-import Panel from './Panel';
+import Panel, { panelClasses } from './Panel';
 import PanelHeader from './PanelHeader';
 
 export {
@@ -11,5 +11,6 @@ export {
   InnerPanelBody,
   InnerPanelHeader,
   Panel,
+  panelClasses,
   PanelHeader,
 };