Add snooze support for calendar reminders (toast UI, service, DB) (#825)

* Filter reminder snooze options by default reminder

* Some updates.

* Fixing empty welcome page issue and attendee loading.

* Icon system for notifications and snooze options etc.

Wino.Core.Domain/CalendarReminderSnoozeOptions.cs

@@ -0,0 +1,29 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Wino.Core.Domain;
+
+public static class CalendarReminderSnoozeOptions
+{
+    private static readonly int[] SupportedSnoozeMinutes = [5, 10, 15, 30];
+
+    public static IReadOnlyList<int> GetSupportedSnoozeMinutes()
+        => SupportedSnoozeMinutes;
+
+    public static IReadOnlyList<int> GetAllowedSnoozeMinutes(long reminderDurationInSeconds, long defaultReminderDurationInSeconds)
+    {
+        var reminderMinutes = (int)Math.Max(0, reminderDurationInSeconds / 60);
+
+        if (reminderMinutes <= 0)
+            return [];
+
+        var maxSnoozeMinutes = reminderMinutes;
+        var defaultReminderMinutes = (int)Math.Max(0, defaultReminderDurationInSeconds / 60);
+
+        if (defaultReminderMinutes > 0)
+            maxSnoozeMinutes = Math.Min(maxSnoozeMinutes, defaultReminderMinutes);
+
+        return SupportedSnoozeMinutes.Where(minutes => minutes <= maxSnoozeMinutes).ToArray();
+    }
+}