UnitOfWork compltely removed. GetDbContext now returns a NadekoContext. Changed every access to contect via uow._context to uow

src/NadekoBot/Services/Settings/BotConfigMigrator.cs

@@ -22,7 +22,7 @@ namespace NadekoBot.Core.Services
         public void EnsureMigrated()
         {
             using var uow = _db.GetDbContext();
-            using var conn = uow._context.Database.GetDbConnection();
+            using var conn = uow.Database.GetDbConnection();
             
             // check if bot config exists
             using (var checkTableCommand = conn.CreateCommand())

src/NadekoBot/Services/Settings/GamblingConfigMigrator.cs

@@ -21,7 +21,7 @@ namespace NadekoBot.Core.Services
         public void EnsureMigrated()
         {
             using var uow = _db.GetDbContext();
-            using var conn = uow._context.Database.GetDbConnection();
+            using var conn = uow.Database.GetDbConnection();
             Migrate(conn);
         }