Ability to scan subfolders only

[Jorge-Rodriguez]

When a repository has a multitude of separate components organized into their own folders, running tfsec on the entire workspace can become very time consuming, all to potentially report misconfiguration that we are not necessarily interested in at the moment.

It would be useful to be able to run tfsec only in a selected folder. There could be a contextual option in the same way that we can currently mark a folder to be ignored