Configurable Tcp settings to CosmosClientOptions

[kirankumarkolli]

Configurable Tcp settings to CosmosClientOptions

public class ComsosClientOptions
{
   ...
  public Nullable<TimeSpan> IdleTcpConnectionTimeout { get; set; }
  public Nullable<int> MaxRequestsPerTcpConnection { get; set; }      
  public Nullable<int> MaxTcpConnectionsPerEndpoint { get; set; }
  public Nullable<TimeSpan> OpenTcpConnectionTimeout { get; set; } 
   ...
}

[ausfeldt]

Thanks.

[kirankumarkolli]

ValidateAsync is the failing one, unrelated to this PR.