Don't hardcode Krovak parameters

[jidanni]

We read https://manifold.net/doc/mfd9/krovak_oblique_conformal_conic_projection.htm
and it looks great. But in PROJ's version,
https://proj.org/en/9.3/operations/projections/krovak.html

The latitude of pseudo standard parallel is hardcoded to 78.5° and the ellipsoid to Bessel.

How unfortunate.

Could these please just be made to be defaults, and not hardcoded.

Thus no scripts would be broken, and one could apply the projection to other than just one area of the earth.

Or, mention on the document how to workaround the hardcoding, via https://proj.org/en/9.3/operations/projections/ob_tran.html .