Phpcs error cleanup – IpUtils class renaming (part 1)

As the last part of phpcs cleanup, we plan to rename the file iputils.php to adhere to our naming standards. To increase the safety of this change, it only adds the new file. Next changes will actually start using the new file. This is a follow-up of a previous cleanup where this file was cleaned up.

https://github.com/Automattic/vip-go-mu-plugins/pull/1937

#mu-plugins #code-standards