Add app wide snackbar

ui/src/actions/snackbarActions.ts

@@ -0,0 +1,12 @@
+export const CLOSE_SNACKBAR = "CLOSE_SNACKBAR";
+
+interface CloseSnakbarAction {
+  type: typeof CLOSE_SNACKBAR;
+}
+
+// Union of all snackbar related action types
+export type SnackbarActionTypes = CloseSnakbarAction;
+
+export function closeSnackbar() {
+  return { type: CLOSE_SNACKBAR };
+}