- 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/MusicPlayerSettingsExtensions.cs

@@ -0,0 +1,30 @@
+using System.Threading.Tasks;
+using Microsoft.EntityFrameworkCore;
+using NadekoBot.Core.Services.Database.Models;
+
+namespace NadekoBot.Db
+{
+    public static class MusicPlayerSettingsExtensions
+    {
+        public static async Task<MusicPlayerSettings> ForGuildAsync(this DbSet<MusicPlayerSettings> settings, ulong guildId)
+        {
+            var toReturn = await settings
+                .AsQueryable()
+                .FirstOrDefaultAsync(x => x.GuildId == guildId);
+
+            if (toReturn is null)
+            {
+                var newSettings = new MusicPlayerSettings()
+                {
+                    GuildId = guildId,
+                    PlayerRepeat = PlayerRepeatType.Queue
+                };
+
+                await settings.AddAsync(newSettings);
+                return newSettings;
+            }
+
+            return toReturn;
+        }
+    }
+}