Enhance the feature and offline capacity of tracker client

#1 ALL TRACKED ENTITY SUPPORT:

Use case: Right now (the 2.15 beta and the incoming 2.15 release version) is hard coded to support for Patient use case. In order to be able to apply to other usecase, the app need to be rewrite the model to adapt with the server for generic tracked entity

Technical Implementation: change the name of the model from Patient to TrackedEntity as well as other patient-related object. Download and store TrackedEntity object from server.

Estimate: 3 working days

#2 DATAENTRY FOR OFFLINE PATIENT:

Use case: the current tracker client support for offline patient registration but does not support for offline patient data entry. Some area where mobile internet is not available will need a full offline capacity.

Technical Implementation: add ability to search for offline patient as well as add data entry screen in the work flow of patient registration.

Estimate: 2 working days

#3 Visit Schedule:

Use case: everyday, health worker need to know who they will deal with. As a result, a visit schedule with information about patient that they will meet in this specific day will be useful.

Technical Implementation: download and display the Visit Schedule from server. Link the patient with the offline patient if possible. The range (time frame) for update the visit schedule need more discuss.

Estimate: 3 working days