Add Autofac.Extensions.DependencyInjection to Volo.Abp.Autofac module.

[maliming]

It would be simpler if autofac made the AutofacServiceProvider class public. autofac/Autofac.Extensions.DependencyInjection#85

builder.RegisterType<AutofacServiceProvider>().As<IServiceProvider>().ExternallyOwned();

var autofacServiceScopeFactory = typeof(AutofacServiceProvider).Assembly.GetType("Autofac.Extensions.DependencyInjection.AutofacServiceScopeFactory");
if (autofacServiceScopeFactory == null)
{
	throw new AbpException("Unable get type of Autofac.Extensions.DependencyInjection.AutofacServiceScopeFactory!");
}
builder.RegisterType(autofacServiceScopeFactory).As<IServiceScopeFactory>();