feat(bisaya-course): enhance German course content and localization support

- Updated the create-german-for-bisaya-course-content.js script to improve lesson pattern retrieval by introducing a new function for generating a lesson pattern pool.
- Added new exercises for various topics including 'Wohnung & Nachbarn', 'Besuch empfangen', 'Arzt, Apotheke, Termin', and 'Amt, Dokumente, Anmeldung', enhancing practical language skills for learners.
- Improved localization by integrating translation keys for various UI elements and error messages across multiple components, ensuring a consistent user experience in both German and Bisaya.
- Enhanced the main.js file to recognize Bisaya language preferences in browser settings, improving accessibility for users.

frontend/src/i18n/locales/ceb/error.json

@@ -0,0 +1,7 @@
+{
+    "error": {
+        "title": "Adunay nahitabo nga sayop",
+        "close": "Isira",
+        "credentialsinvalid": "Dili husto ang imong login data."
+    }
+}