Replaced a direct object return statement with an ObjectWrapper
ServiceResponse which now handles returning an object. The
ServiceResponse should be extended with methods to set the HTTP status
and to check if the object in the ServiceResponse is null.

Change-Id: I11e3fcf65710827aca9a67a8402312d769cc815b
Signed-off-by: Peter Merkert <p.merkert@sap.com>