CEC-4640: add bulk add to fleet (#384)

* refactor bulkactions component

* refactor bulk actions

* update dom tests

* add addToFleet hook

* make signal optional

* implement code splitting

* add deps

* remove test label

src/services/__mocks__/fleetsAPI.js

@@ -62,9 +62,9 @@ const fleetsAPI = {
   getFleetVehicles: async () => {
     return { data: vehicles };
   },
-  addFleetVehicles: async (_name, vehicle) => {
-    vehicles.push(...vehicle.vins);
-    return vehicle;
+  addFleetVehicles: async (_name, payload) => {
+    payload.vins && vehicles.push(...payload.vins);
+    return payload;
   },
   deleteFleetVehicle: async (_name, vehicle) => {
     const index = vehicles.findIndex(element => element === vehicle.vin);