(ci): add cmake validator

Description

It could a benefit for our project to provide some warning about modern-cmake usage violation.

Something like this python tools: https://pypi.org/project/cmake-checker/

Sheldon would provide warnings in a first time.

Proposal

Integrate cmake-checker in sheldon, only as warnings for now.

cmake-checker has not been updated since 3 years. cmake-format / cmake-lint is a far better option. Bonus: same set of option between the linter and the formater.

see sight!639 (merged) for a proposal of cmake-lint