Create class Request
Add constants for methods
Add class field
Add constructor
Add methods to control the class fields

 - Add method getArg
 - Add method getBaseUrl
 - Add method setArg
 - Add method setBaseUrl
 - Add method setSharedSecret
 - Add method addArg
 - Add method clearArg
Add methods to create Url

 - Add method createUrl
 - Add method signedRequest
 - Add method unsignedRequest
Add signal and slot to handle the response

 - Add signal processingComplete
 - Add slot processTheResponse
Add method sendRequest