feat(dashboard,medusa,ui): Manual gift cards + cleanup (#6380)

**Dashboard**
- Adds different views for managing manual/custom gift cards (not associated with a product gift card).
- Cleans up several table implementations to use new DataTable component.
- Minor cleanup of translation file.

**Medusa**
- Adds missing query params for list endpoints in the following admin domains: /customers, /customer-groups, /collections, and /gift-cards.

**UI**
- Adds new sizes for Badge component.

**Note for review**
Since this PR contains updates to the translation keys, it touches a lot of files. For the review the parts that are relevant are: the /gift-cards domain of admin, the table overview of collections, customers, and customer groups. And the changes to the list endpoints in the core.

packages/admin-next/dashboard/src/i18n/config.ts

@@ -6,22 +6,27 @@ import { initReactI18next } from "react-i18next"
 
 import { Language } from "./types"
 
-i18n
+void i18n
   .use(Backend)
   .use(LanguageDetector)
   .use(initReactI18next)
   .init<HttpBackendOptions>({
-    fallbackLng: "en",
+    fallbackLng: "en-US",
+    load: "languageOnly",
     debug: process.env.NODE_ENV === "development",
     interpolation: {
       escapeValue: false,
     },
+    backend: {
+      // for all available options read the backend's repository readme file
+      loadPath: "/locales/{{lng}}/{{ns}}.json",
+    },
   })
 
 export const languages: Language[] = [
   {
-    code: "en",
-    display_name: "English",
+    code: "en-US",
+    display_name: "English (US)",
     ltr: true,
     date_locale: enUS,
   },

packages/admin-next/dashboard/src/i18n/types.ts

@@ -1,5 +1,5 @@
 import type { Locale } from "date-fns"
-import en from "../../public/locales/en/translation.json"
+import en from "../../public/locales/en-US/translation.json"
 
 const resources = {
   translation: en,