Refactor i18n settings and improve language load handling

This update separates the creation of i18n settings into its own function (@kit/i18n) and enhances the handling of language and namespace loading in i18n.client. It tracks loaded languages and namespaces, and prevents rendering if none are loaded or after a maximum number of iterations. The usage of Suspense has also been modified in root-providers to employ a null fallback.

packages/i18n/package.json

@@ -10,6 +10,7 @@
   },
   "prettier": "@kit/prettier-config",
   "exports": {
+    ".": "./src/index.ts",
     "./server": "./src/i18n.server.ts",
     "./client": "./src/i18n.client.ts",
     "./provider": "./src/i18n-provider.tsx"