[Geo] Enable primatives / marks to be geo-aware (similar to Canvas)

[techniq]

Similar to how a primitive/mark detects the rendering context (svg/canvas) and renders accordingly, it would be useful to do similar with the geo context.

For example, GeoPoint could be removed/consolidated with Point / Points.

Also useful for Text and likely others.

Possibly GeoSpline (although is currently more of a GeoLoftedSpline)