Allow static checks to be run against an arbitrary path

[joemcgill]

Currently the WP CLI command is limited to only run checks against plugins that are installed on the same site as Plugin Check.

This is because it eventually calls the Plugin_Request_Utility::get_plugin_basename_from_input() method during the setup process which throws an Exception if the plugin is not installed.

To satisfy the requirements of #441 (comment), we need to be able to run checks against a plugin that is located outside the WordPress filesystem, e.g. /tmp.

Ideally, this would work by passing a CLI command like:

wp plugin check /tmp/plugin-path

When the path is not to an active plugin, only static checks should be eligible to be run.

[swissspidy]

Related:

• Rethink the WP-CLI approach #153

[davidperezgar]

Yes! It's necessary for the form submission.

[davidperezgar]

I've commited first approach how to use in an arbitrary path. It's working. Only rename variables would need it.