`csfilter-kfp` should take directory as an argument

[siteshwar]

csfilter-kfp searches for false positives only from root directory of the git repository. It should accept directory as an argument to make the known false positives repository better organized.

[kdudka]

As discussed in person, I do not think this should be configured explicitly by an option. The tool should automatically recognize the structured version of the KFP repository and look for the data in the correct directory (or directories). We yet need to think about the correct directory structure and the way how it can be reliably distinguished from the flat structure that we use today.