Cythonize ElementWrapper and make parent the first argument

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For speed and consistency.

Depends on #14143
Depends on #14015
Depends on #14516

CC: @sagetrac-sage-combinat @nthiery @simon-king-jena

Component: performance

Keywords: cython ElementWrapper

Author: Travis Scrimshaw

Reviewer: Nicolas M. Thiéry

Merged: sage-5.12.beta2

Issue created by migration from https://trac.sagemath.org/ticket/14519

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Dependencies: #14143 #14516

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comment:1

Initial version which has a dependencies on #14143 (minor reject) and #14516 (since Letter no longer inherits from ElementWrapper, there is nothing to do there). Both of which this can be moved past with minor-moderate cost.

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Work Issues: fix segfault in UCF

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comment:3

The UCF segfault was due to it inheriting from both FieldElement and ElementWrapper. In particular, the _add_() / _mul_() / etc. functions of the UCF elements were not being called when ElementWrapper is an extension class. It also segfaults when I have it inherit from CombinatorialFreeModuleElement, which is what it wraps. I'll see if I can reduce it down to a simple test case and post it on another ticket and sage-devel since I don't know if this is a python, cython, or sage bug...

Also #11931 can be closed as a duplicate.

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Changed work issues from fix segfault in UCF to none