Asylkhan Azat

Results 2 issues of Asylkhan Azat

Introduce new abstraction for providing current time to improve testability and make units more independent of environment system is run on. ```csharp public interface ITimeProvider { DateTime Now(); DateTime UtcNow();...

In the SqlMapper.Async [Line 451](https://github.com/DapperLib/Dapper/blob/main/Dapper/SqlMapper.Async.cs#L451) and [Line 1323](https://github.com/DapperLib/Dapper/blob/main/Dapper/SqlMapper.Async.cs#L1323) what is the purpose of calling `Nullable.GetUnderlyingType`, if it is not used afterwards?