Add shape of earth 1 and 7

This PR extends `ellispsoid` to handle `shapeOfTheEarth` value `1` and `7`.

This is a precursor to GDT 4/5.
@pp-mo Nope. The `scale` used depends on the `shape`.

`shape = 3` is in units of `km` and `shape = 7` is in units of `m`. This test ensures the the expected unit scaling given the `shapeOfTheEarth` to `m` is performed correctly.