Profile Mapping Extension

Extension definition for Mapping between ```API``` and ```Profile```. CapabilityStatement.rest.resource.profile has two different profile statements:

• profile - the overall system profile for a resource
• supportedProfile 0..* - a particular profile that the system supports

What is missing from this picture is defining which resources conform to which profile. Sometimes, of course, it's impossible to define this, but quite often, there's an algorithmic relationship that a server or client could use to know that resources with a particular set of values will or should conform to a given profile.

This extension defines a relationship between a search string and a profile. Any resource that meets a given search string will be expected to conform to the particular profile. If more than one profile is nominated for a search string, resources SHALL conform to all the listed profiles. The last extension can be without a search matches and remaining resources

This extension repeats, and order is important - once a match is found, this profile is the one that applies. Todo: If this extension is useful, it will be moved to the core extensions pack