TRUNK-4485: Modifying provider search to make it configurable

This tickets aims to make search mode for providers when using identifier configurable through the global property. Instead of suing MatchMode.ANYWHERE, the code is modified to allow only EXACT and START.
I agree but I decided to use these distinguishing names because there are match mode constants associated with patient search and their name reflects the fact that they are related to patient searching. Do you think we should change get rid of these and maintain the general naming scheme alone?