Support DI (`OnClientConnected` and `OnClientDisconnected`)

[billhong-just]

Problem to solve

Currently, We have to use clientConnectedArgs.Request.HttpContext.RequestServices.GetRequiredService<T>()
to get needed services from DI. It's not an intended way.

Proposal

A more ASP.NET Core style DI. Maybe something like jamesmh/coravel did.

It allow us to use DI in jobs we create.

• https://docs.coravel.net/Invocables/#_1-generating-a-daily-report-and-emailing-to-users
  
  

References

• #4 (comment)
• https://github.com/jamesmh/coravel