Alignment with OGC sort and property selection?

[philvarner]

Investigate and write up how we would align with OGC sort - https://github.com/opengeospatial/ogcapi-records/blob/master/core/standard/clause_9_sorting.adoc and our fields / their property selection - https://github.com/opengeospatial/ogcapi-features/tree/master/proposals/property-selection

[philvarner]

OGC Records - "Sorting" conformance class. (Draft) Uses the same [+-]name syntax as the Sort Extension. Also requires a "Sortables" endpoint to describe which properties can be sorted on. Filed opengeospatial/ogcapi-features#639 to allow wildcard sortables.

OGC API - Features - (Proposal Draft) Properties Selection - query parameter properties and endpoint returnables. Only operates on unqualified fields in the Properties object. Also has a skip-geometry field. Both the query parameter and endpoints have no conflict with our Fields Extension, and this could easily be another extension. Filed opengeospatial/ogcapi-features#639 to allow wildcard properties