Map matching + link geometries as first-class modules of a SearchApp

[robfitzgerald]

we are currently loading geometries twice, once for the map matching input plugin and also for output geometry construction. this is because 1) these assets are not first-class citizens of a SearchApp, 2) the APIs for input plugins and output plugins do not include a &SearchApp in scope.

we will require some kind of struct that provides methods for both of these features, which encompasses all of the existing features:

• vertex/edge-oriented map matching via vertex or edge rtree, constructed based on configuration selection
• edge geometry output plugin processing for building WKT/WKB/GeoJSON outputs