Normalizes the given design-space coordinates.
The minimum and maximum values for the axis are mapped to the interval [-1,1], with the default axis value mapped to 0.
The normalized values have 14 bits of fixed-point sub-integer precision as per OpenType specification.
Any additional scaling defined in the face's `avar` table is also applied, as described at https://docs.microsoft.com/en-us/typography/opentype/spec/avar
Note: coords_length must be the same as the number of axes in the face, as for example returned by
ot_var_get_axis_count. Otherwise, the behavior is undefined.
| face |
The Face to work on |
| coords_length |
The length of the coordinate array |
| design_coords |
The design-space coordinates to normalize |
| normalized_coords |
The normalized coordinates |