Trac #28109: Renaming and improvement of periodic point methods

Currently, rational_periodic_points() only works over QQ and returns all
the periodic points. We add functionality to make this work over finite
fields. We also add optional parameters for changing the base ring.

We also deprecate rational_periodic_points() and change the name to
all_periodic_points() for consistent naming. We do this under the
direction of Ben Hutz, the original author.

URL: https://trac.sagemath.org/28109
Reported by: gh-Zopherus
Ticket author(s): Eric Zhu, Alex Galarraga, Bianca Thompson
Reviewer(s): Adam Towsley, Jasmine Camero, Olivia Schwager, Ben Hutz