contains search parameter should be defined as an operation

contains search parameter should be redefined as an operation since it is requesting the server perform a calculationg to determine if point a is contained within a Location that is defined by the Location.extension('http://hl7.org/fhir/StructureDefinition/location-boundary-geojson') attachment ( as an URL or base64 encoded geoJSON file.

The attachment is not searchable as defined in FHIR : http://build.fhir.org/search.html#table

Moreover should consider whether doing this is a priority considering that zip codes lists or other address elements can accomplish the same.