Implement internationalization support across components

- Integrated `next-intl` for toast messages and locale handling in various components, including `Providers`, `CanvasUserMenu`, and `CreditOverview`.
- Replaced hardcoded strings with translation keys to enhance localization capabilities.
- Updated `RootLayout` to dynamically set the language attribute based on the user's locale.
- Ensured consistent user feedback through localized toast messages in actions such as sign-out, canvas operations, and billing notifications.

next.config.ts

@@ -1,6 +1,9 @@
 import { withSentryConfig } from "@sentry/nextjs";
+import createNextIntlPlugin from "next-intl/plugin";
 import type { NextConfig } from "next";
 
+const withNextIntl = createNextIntlPlugin();
+
 const nextConfig: NextConfig = {
   turbopack: {
     root: __dirname,
@@ -26,7 +29,7 @@ const nextConfig: NextConfig = {
   },
 };
 
-export default withSentryConfig(nextConfig, {
+export default withSentryConfig(withNextIntl(nextConfig), {
   // For all available options, see:
   // https://www.npmjs.com/package/@sentry/webpack-plugin#options