Fix typos found by codespell

[DimitriPapadopoulos]

I have a separate PR commit for Changelog.md as some projects prefer not modifying the changeleog. I can either revert that commit or squash into a single commit, at your convenience.

[rlejeune74]

Thanks @DimitriPapadopoulos for your contribution, it has been applied internally and will be soon visible in the public repo.