feat: oblique lon lat transformation

[zakrzewow]

No description provided.

[Quba1]

Thank you for your contribution!

Version 0.8 of this crate introduced a slightly different structure of projection constructor, which allows to define optional parameters. Would you be able to adapt your code to this new style?

Also, may I ask you to:

1. Mention in the projection documentation alternative names of this projection (namely that it is sometimes called Rotated Pole).
2. Clearly indicate in the documentation that the output units of the project function are degrees (in contrast to other projections in this crate, which output meters).

Many thanks!

[zakrzewow]

I've adjusted the oblique lon lat transformation implementation to version 0.8. Also, I've clarified the docs.
Please let me know if I should change anything else

[Quba1]

LGTM