feat(bisaya-course, vocabService): expand numerical didactics and enhance lesson progress serialization

- Added new glosses for the numbers sixty, seventy, and eighty in the Bisaya didactics, enriching the numerical curriculum.
- Updated the _serializeLessonProgress method to include an options parameter for suppressing lesson review due notifications based on SRS item status.
- Introduced a new method to check for due SRS items, improving the handling of lesson progress and review scheduling.

backend/scripts/update-bisaya-didactics.js

@@ -356,6 +356,9 @@ export const LESSON_DIDACTICS = {
       { target: 'Traysenta', gloss: 'dreißig' },
       { target: 'Kwarenta', gloss: 'vierzig' },
       { target: 'Singkwenta', gloss: 'fünfzig' },
+      { target: 'Sesenta', gloss: 'sechzig' },
+      { target: 'Setenta', gloss: 'siebzig' },
+      { target: 'Otsenta', gloss: 'achtzig' },
       { target: 'Nobenta', gloss: 'neunzig' }
     ],
     grammarFocus: [