Code for guessing the parameters of k-regular sequences from the first few entries of a list/sequence/etc.

See also Meta ticket #21202.

Depends on #21319

CC: @rwst

Component: combinatorics

Author: Daniel Krenn

Branch/Commit: u/cheuberg/sequences/k-regular-guess @ ae06d17

Reviewer: Clemens Heuberger

Issue created by migration from https://trac.sagemath.org/ticket/21204