Warn for use of eval

[Eneroth3]

Evaluating code from external sources may be a security concern. Add a cop catching the use of eval (and similar methods) and warn of the risks.

[thomthom]

There is an RuboCop for eval: https://www.rubydoc.info/gems/rubocop/RuboCop/Cop/Security/Eval

But, maybe it's still worth to have one for the context of SketchUp? So if you run only SketchUp cops it's still being reported?