Add PHPCSUtils dependency and implement the use of it

[jrfnl]

A lot of the utility functions for PHPCS which I've written over the years and are included in WPCS and/or PHPCompatibility will soon be published in a separate repo called PHPCSUtils.

Once that repo has been published and the first version is tagged, this repo should become a require dependency for YoastCS and use of the utility methods in that repo should be implemented.

Both WPCS as well as PHPCompatibility will start using that repo too in their next major release.

The YoastCS version which implements PHPCSUtils should be a new major release and should at the same time update the WPCS and PHPCompatibility dependencies to the versions using PHPCSUtils as well.

[jrfnl]

Related to #208