Add Plugin Check workflow

[adamsilverstein]

Description

Plugin Check is a plugin checking tool developed by the WordPress core team (see original proposal). This tool is used as part of the plugin review process and will help ensure this plugin’s codebase remains up-to-date with the base required standards from the Plugin Review team. The tool includes both static and runtime checks and an ever-growing list of checks for various plugin development requirements and best practices.

Details

The plugin check can be run automatically using a GitHub action and the results of the Plugin Check analysis will be added in the form of annotations on new pull requests.
Specific groups of checks can be enabled or disabled using the checks attribute. For an initial implementation, I suggest enabling all checks. As the Plugin Check grows to include more tests, the list run in the automated action can be trimmed to whatever is preferred here.

Pull request

I have prepped this PR for your review - #20808