Pooled client authentication

[zairnamlas]

It may be already available in the api, but I wanted to check whether a client retrieved from pool is already authenticated.
I'm doing the AuthAsync every time after getting the client from pool which is un-necessary for already authenticated ones.

Thanks

[zairnamlas]

Just randomly visited this after a long time. Forgot to put a workaround for this

Introduced the property in IRedisClient
bool IsAuthenticated { get; set; }

Setting its value to true after authentication and next time after getting it from Pool just checking if it is already true.

I hope it will help someone.