Add CI tests on Windows

[kadykov]

The aim of this PR is to improve automatic test coverage of the CI actions by launching the same tests on Linux and Windows

Fixes #760

[martindurant]

This requires #759 to pass?

[kadykov]

Yes, but I'm afraid it is not sufficient.
In any case, I think it is better to launch the tests on both platforms.

[martindurant]

I only see a couple of path-related failures, and I presume your other PR fixes at least one of them

[martindurant]

OK, just the one failure. Will you have the chance to track this down?

[kadykov]

Yes, I have to check once agian #743

[kadykov]

As far as I understand, using postgresql fixture from pytest-postgresql is not fully supported on Windows, so I skipped these tests on Windows.

[martindurant]

Seems like we should also posixiify the sqlite_with_data path in the duckDB test. Not sure if the reader should do that.

[kadykov]

I agree, that we should not posixify the path in the DuckDB reader.

The problem was not with the posixification, but with the protocol extraction, that we also should not do there.

[martindurant]

A couple of small suggestions.

[kadykov]

I combined Windows and Linux test jobs with a matrix.
Now this PR is ready to be merged.