Modifies eig_p and related operations to take advantage of the new jaxlib geev API (#4266)
* Add options to compute L/R eigenvectors in geev.
The new arguments are by default set to True to ensure backwards
compatibility between jaxlib and jax.
Reformulate eig-related operations based on the new geev API.
* Addressed hawkinsp's comments from google/jax#3882.
Co-authored-by: Skye Wanderman-Milne <skyewm@google.com>