Improvements for morphisms of ModulesWithBasis

[nthiery]

This ticket implements:

• inverses for morphisms of finite dimensional vector spaces
• tensor products of morphisms
  and improves:
• triangular morphisms over base rings

Declares CombinatorialFreeModule indexed by a finite set as being finite dimensional.

Depends on #10668
Depends on #17160

CC: @sagetrac-sage-combinat

Component: categories

Keywords: homsets, module morphisms, days64

Author: Nicolas M. Thiéry

Branch/Commit: 71b36da

Reviewer: Franco Saliola

Issue created by migration from https://trac.sagemath.org/ticket/8678

[nthiery]

Description changed:

--- 
+++ 
@@ -1,5 +1,8 @@
-The upcoming patch in the Sage-Combinat queue will implement:
+The upcoming patch in the Sage-Combinat queue implements:
 - inverses for morphisms of finite dimensional vector spaces
 - tensor products of morphisms
 
-At this occasion, it will start a bit of cleanup in the category framework for homsets
+and improves:
+- triangular morphisms over base rings
+
+At this occasion, it starts a bit of cleanup in the category framework for homsets, fixing some known issues (failing _test_category).

[nthiery]

Changed keywords from homsest to homsets, module morphisms

[saraedum]

comment:3

This is is a very old ticket. Anyway, can I find the patch that fixes _test_category somewhere? This also fails for #15154. Or should I just disable these tests?

[saraedum]

comment:4

Replying to @saraedum:

This is is a very old ticket. Anyway, can I find the patch that fixes _test_category somewhere? This also fails for #15154. Or should I just disable these tests?

Since there is no reply here, I created a partial fix at #15232.