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.
Do you need the `np.array(...)`?

```
>>> np.ma.masked_equal([1, 2, 3], 2)
masked_array(data = [1 -- 3],
             mask = [False  True False],
       fill_value = 2)
```