[IMP] views_migration_17: support alternative output directory for transformed views instead of in-place write

[rrebollo]

• Introduce a new method to handle file writing that allows specifying an alternative output directory via an environment variable
• Update documentation to reflect the new output directory option.
• Remove the unused str2bool function

Fix #2793 More context in Tecnativa/doodba-copier-template#509

@BinhexTeam

[jguenat]

(for doodba user you can also temporary change the bind volume /odoo/custom to rw in devel.yaml)

[OCA-git-bot]

This PR looks fantastic, let's merge it! Prepared branch 17.0-ocabot-merge-pr-3189-by-pedrobaeza-bump-minor, awaiting test results.

[pedrobaeza]

Let's see if a rebased branch is green.

[OCA-git-bot]

Congratulations, your PR was merged at 5701c536da2601071b438ffe1c2fcaf177da0739. Thanks a lot for contributing to OCA. ❤️