Allow HL7 processor to allow lab updates for patients who don't yet exist in the system

Right now, if an independent lab system tries to send an HL7 update to indicate a patient result, and that patient can't be found in the system by their identifier, the attempt to handle the HL7 message results in an error. Instead, allowing a new patient record to be created at the same time the new observation is entered would allow a remote lab system to send all of its results to an instance of OpenMRS without having to worry about whether or not the patient already exists.