- Database namespace is now NadekoBot.Db

- Db related code is now in src/NadekoBot/Db
- Finished major part of the db refactor, but many optimizations are left to be made

src/NadekoBot/Db/Extensions/ReminderExtensions.cs

@@ -0,0 +1,22 @@
+using NadekoBot.Core.Services.Database.Models;
+using Microsoft.EntityFrameworkCore;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace NadekoBot.Db
+{
+    public static class ReminderExtensions
+    {
+        public static IEnumerable<Reminder> GetIncludedReminders(this DbSet<Reminder> reminders, IEnumerable<ulong> guildIds) 
+            => reminders.AsQueryable()
+                .Where(x => guildIds.Contains(x.ServerId) || x.ServerId == 0)
+                .ToList();
+
+        public static IEnumerable<Reminder> RemindersFor(this DbSet<Reminder> reminders, ulong userId, int page)
+            => reminders.AsQueryable()
+                .Where(x => x.UserId == userId)
+                .OrderBy(x => x.DateAdded)
+                .Skip(page * 10)
+                .Take(10);
+    }
+}