Architecture_Engine : Grids - curves should not be projected

The grid constructor currently projects all ICurves to Plane.XY. Some of these curve projections aren't implemented (hence some pull functions not working at the moment). Projecting curves to an empty XY plane will have unintended consequences for a user (for example, primitive geometry will become complex and no longer able to parameterise). Project to plan should either be removed altogether, or curves planes tested to see if they are parallel to XY then translating (not projecting). Any curves not parallel to XY will be rejected, but since every use-case of an architectural grid should be XY, there should be very few exceptions raised.