Enhancement: Support WP VIP Code Standards

[jamesmorrison]

Is your enhancement related to a problem? Please describe.
During a commit of Distributor to a WP VIP Go repository, the VIP Bot flagged a number of issues with the plugin codebase. [For privacy reasons, the site in question is not being identified here - contact me directly for further details.]

Describe the solution you'd like
Include the VIP code standards in tests, ensure that where practical code is updated for compatibility; where impractical PHPCS ignore rules are added.

Designs
N/A

Describe alternatives you've considered
N/A (The only alternative is not to use VIP Go)

Additional context
N/A

[jeffpaul]

Here’s the ClassifAI PR that added VIPCS and fixed/ignored VIPCS issues: 10up/classifai#287. We would theoretically take a similar approach here.