improves testability of ClientRequest
improves testability of ClientRequest

Internal properties like url, host, scheme etc are public (read only).
NSURL behaves in the same way.

(cherry picked from commit 86eef1eabe3998de9cc68bc75a1fd6fc1d1762c5)

IBM-Swift/Kitura-net,naithar/Kitura-net,IBM-Swift/Kitura-net,IBM-Swift/Kitura-net,IBM-Swift/Kitura-net