Get conditions or patient-diagnosis by patient

The REST API does not currently support searching for the conditions of a patient, nor the diagnoses of a patient. See https://talk.openmrs.org/t/search-condition-or-patient-diagnosis-via-rest-api/37571.

Implement the following...

Conditions

• Resource: `/condition`
• Parameter `patient`: UUID of patient
• Parameter `includeInactive` (optional): If true, return all conditions of patient; if absent or false, return only active ones.

Patient diagnoses

• Resource: `/patientdiagnoses`
• Parameter `patient`: UUID of patient
• Not sure if we should allow filtering on certainty?