BUG: sparse: fix 1D for vstack/hstack and Improve 1D error msgs in h/v-stacks/kron/kronsum

[dschult]

Fixes #21064

Some construction functions (like hstack and vstack) do not handle 1D input well for some formats. The shape was assumed to be 2D and not checked for 1D. This PR:

• adds tests for these cases,
• adds tests for better error messages in functions kron and kronsum when 1D input it used,
• fixes ndim/shape related errors in _construct.py by using _shape_as_2d where needed

This might be too late, but if possible, it would be good to get this into 1.14.1. @tylerjereddy

[tylerjereddy]

This might be too late, but if possible, it would be good to get this into 1.14.1.

Should be fine unless the review takes forever. I don't have a concrete timeline for 1.14.1 just yet, was hoping to do a little bit of coding/code review before jumping on another release right away.

[perimosocordiae]

Thanks for fixing this, Dan. I left some optional tweaks to the kronsum error messages.

[perimosocordiae]

Oops, didn't realize the test would fail:

    def test_kronsum_ndim_exceptions(self):
>       with pytest.raises(ValueError, match='is not 2D'):
E       AssertionError: Regex pattern did not match.
E        Regex: 'is not 2D'
E        Input: 'kronsum requires 2D inputs. `B` is 1D.'

[perimosocordiae]

Merged! Thanks @dschult