Add ability to retrieve full set of GeographicCRSProps before a CRS is set on an iModel

[ben-polinsky]

I'm working on enabling the setting of a Coordinate Reference System (CRS) during the creation of an iModel to address alignment issues during data synchronization. As users decide between the extensive list of GCS' returned, it would be beneficial to display additional data such as the CRS unit, datum info, and ellipsoid info. This would help them make an informed decision. Currently, only the name, description, extent, and deprecated status are shown. (After iModel creation, the full set of properties is available through an iModel's geographicCoordinateSystem getter.)

If it is prohibitively expensive to optionally return this information through getAvailableCoordinateReferenceSystems, perhaps we could open an API to get the full properties for a single CRS one at a time?