feat(calendar): add reminder functionality for events with notifications

src/i18n/en.json

@@ -510,6 +510,14 @@
     "linkedRoom": "Linked Room",
     "noRoom": "No room (no video meeting)",
     "linkedRoomHint": "Link a room to automatically include the join-URL in the event.",
+    "reminderLabel": "Reminder",
+    "reminderNone": "No reminder",
+    "reminder5": "5 minutes before",
+    "reminder15": "15 minutes before",
+    "reminder30": "30 minutes before",
+    "reminder60": "1 hour before",
+    "reminder120": "2 hours before",
+    "reminder1440": "1 day before",
     "timezone": "Timezone",
     "color": "Color",
     "eventCreated": "Event created!",