Phpcs error cleanup – IpUtils class renaming

As the last part of phpcs cleanup, we renamed iputils.php file to adhere to our naming standards. To increase the safety of this change was done in 3 steps. This is the last step in that process including the removal of the now unused file under the original name.

https://github.com/Automattic/vip-go-mu-plugins/pull/1947

#mu-plugins #code-standards