refactor: make instances as `Ref` & apply type `GFC`

.eslintrc.js

src/_app/App.tsx

src/common/constants/index.js

src/common/instances/Connector.ts

src/common/instances/Socket.ts

src/common/types/fc.ts

src/contexts/bottom-sheet/index.tsx

src/contexts/cart/index.tsx

src/contexts/toast/index.tsx

src/pages/admin-page/AdminPage.tsx

src/pages/cart-page/CartPage.tsx

src/pages/history-page/HistoryPage.tsx

src/pages/login-page/LoginPage.tsx

src/pages/main-page/MainPage.tsx

src/pages/menu-page/MenuPage.tsx

src/pages/order-page/success-page/SuccessPage.tsx

src/pages/signup-page/SignupPage.tsx