[Aleph rest-dlf connector] Refactored AlephRequestHandler & AlephRequestItemHandler .. & renamed XMLBuilder to RequestItemXMLBuilder
AlephRequestItemHandler was used to:
1) parse List of RequestedItem in order to forward those into LookupUser service
2) handle RequestItem service (parse error, sequenceNo, RequestId)
3) handle CancelRequestItem service (parse requestId, whether can be Request deleted, sequenceNo & also errors)
AlephRequestHandler was used to:
1) handle LookupRequest - find Request, get it's link & parse that request info to fit into LookupRequestResponseData

Now the situation is:
AlephDoRequestHandler was created to handle RequestItem, CancelRequestItem services
AlephLookupRequestsHandler was created to handle parsing all user's requests at once to satisfy LookupUser's needs
AlephLookupRequestHandler was created to handle LookupRequest & it's specific needs related to LookupRequestResponseData

Also refactored appropriate methods within RestDlfConnector