InteractiveLPProblem, dictionaries: add_constraint / add_row methods

[mkoeppe]

This ticket adds add_constraint and add_row methods.
Following the suggestion at
#18805 comment:27
these methods create new problems / dictionaries, leaving the original ones unmodified.

(Split out from the larger ticket #18805.)

Depends on #20500

CC: @novoselt @pgxiao

Component: linear programming

Author: Peijun Xiao, Matthias Koeppe, Andrey Novoseltsev

Branch/Commit: c8559f3

Reviewer: Andrey Novoseltsev

Issue created by migration from https://trac.sagemath.org/ticket/20559

[mkoeppe]

Branch: u/mkoeppe/interactivelpproblem__dictionaries__add_constraint___add_row_methods

[mkoeppe]

Commit: 5849980

[mkoeppe]

New commits:

d6ee048	Refactor leaving_coefficients in terms of new method row_coefficients
3cbdeef	Fixup
db52d0e	Add @abstract_method methods to LPAbstractDictionary
4e9955e	Refactor entering_coefficients in terms of new method column_coefficients
a382ec1	Fix documentation
b292e63	Merge branch 't/20500/lpabstractdictionary__refactor_leaving_coefficients__entering_coefficients_using_new_methods_row_coefficients__column_coefficients' into t/20559/interactivelpproblem__dictionaries__add_constraint___add_row_methods
5849980	InteractiveLPProblem, dictionaries: add_constraint / add_row methods

[mkoeppe]

Dependencies: #20500

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

639865c	Merge tag '7.2.rc1' into t/20559/interactivelpproblem__dictionaries__add_constraint___add_row_methods
f5b3900	add_row: Use @abstract_method

[sagetrac-git]

Changed commit from 5849980 to f5b3900

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

f9c5448

fixup

[sagetrac-git]

Changed commit from f5b3900 to f9c5448

[novoselt]

Reviewer: Andrey Novoseltsev

[novoselt]

Work Issues: rebasing

[sagetrac-git]

Changed commit from f9c5448 to 2d444bc

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

d9a6356	InteractiveLPProblem, dictionaries: add_constraint / add_row methods
77e0a00	add_row: Use @abstract_method
2d444bc	fixup

[mkoeppe]

comment:8

Rebased on 7.3.beta0