feat: add null to possbile values of of id-type of useGet (#35)

Author: anbraten

src/useGet.ts

@@ -9,7 +9,7 @@ function loadServiceEventHandlers<
   M,
 >(
   service: FeathersService<CustomApplication, ServiceTypes<CustomApplication>[T]>,
-  _id: Ref<Id | undefined>,
+  _id: Ref<Id | undefined | null>,
   data: Ref<M | undefined>,
 ): () => void {
   const onCreated = (item: M): void => {
@@ -64,13 +64,13 @@ export type UseGetFunc<CustomApplication> = <
   M = ServiceModel<CustomApplication, T>,
 >(
   serviceName: T,
-  _id: Ref<Id | undefined>,
+  _id: Ref<Id | undefined | null>,
 ) => UseGet<M>;
 
 export default <CustomApplication extends Application>(feathers: CustomApplication) =>
   <T extends keyof ServiceTypes<CustomApplication>, M = ServiceModel<CustomApplication, T>>(
     serviceName: T,
-    _id: Ref<Id | undefined>,
+    _id: Ref<Id | undefined | null>,
     { disableUnloadingEventHandlers } = { disableUnloadingEventHandlers: false },
   ): UseGet<M> => {
     const data = ref<M>();