- 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/Services/CommandHandler.cs

@@ -17,6 +17,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using NadekoBot.Core.Common.Configs;
 using NadekoBot.Core.Services.Impl;
+using NadekoBot.Db;
 using NadekoBot.Modules.Administration;
 using Serilog;