Add file-or-directory-existence rule

[drgs]

Motivation

Sometimes we might need to check whether a repository contains at least one directory or file whose name matches a certain regular expression. Although file-existence and directory-existence rules exist, these two can not be combined within one single rule.

Proposed Changes

This PR implements a file-or-directory-existence rule which aims at checking whether there is at least one file or directory specified in globsAny whose name matches a regular expression.

Test Plan

• it returns a passed result if both files and directories exist matching the given pattern
• it returns a passed result if only files exist matching the given pattern
• it returns a passed result if only directories exist matching the given pattern
• it returns a failed result if neither files or directories exist matching the given pattern