Split analysis and tests

[alecandido]

Sometimes Pylint errors are preventing the whole unit tests to run, possibly hiding some further failures.

While in principle it is fine to have a reasonable code before testing, whenever there are Pylint errors are usually localized to some small portions of the code, and they would not cause the whole unit tests to fail.

I propose to make the two jobs independent, even keeping them inside a single workflow. Moreover, we do not need to run Pylint on all the combinations of matrix on which we run unit tests, it is sufficient to iterate Python versions, while linting errors should not depend on the os/architecture.

[alecandido]

@scarrazza before starting I'd like to have your opinion.

[scarrazza]

The idea of splitting, looks sensible to me, so you have my endorsement.