feat(auth): add an RFC complient validation function for an email address; cover it with tests

src/features/auth/model/stores/authStore/authStore.ts

@@ -4,6 +4,7 @@ import { login, logout, register } from "../../../api";
 import { callApi } from "shared/utils";
 import { UNEXPECTED_ERROR_MESSAGE } from "shared/api";
 import { selectAuthData, selectFormValid } from "../../selectors";
+import { validateEmail } from "../../../lib";
 
 export const defaultStoreState: Readonly<AuthStoreState> = {
   formData: {
@@ -15,10 +16,6 @@ export const defaultStoreState: Readonly<AuthStoreState> = {
   error: null,
 };
 
-function validateEmail(email: string): boolean {
-  return Boolean(email);
-}
-
 function validatePassword(password: string): boolean {
   return Boolean(password);
 }