WithinSpace Explanation and new CoordinateSystem node

[antongit]

Is your feature request related to a problem? Please describe.

1. WithinSpace node doesn't have a good Explanation patch.
2. AxisAndGrid node is not that good as Coordinate System visualizer, proposing CoordinateSystem node, that should be used instead or replace the current AxisAndGrid.

Describe the solution you'd like
See Explanation Custom Space that uses the CoordinateSystem [Layer] in this commit: 6865f4d.