Add a checksum check for plugins from the official plugin directory

[Zodiac1978]

There is an official Plugin API endpoint to get the checksums.

Sample file: https://downloads.wordpress.org/plugin-checksums/plugin-report/2.1.1.json

As I use Plugin Report to check an installation for issues, highlighting modified plugins could be a great addition to this plugin.

For example implementations (for core), we could look at the Health Check plugin:
https://github.com/WordPress/health-check/blob/trunk/HealthCheck/Tools/class-health-check-files-integrity.php

I think there are more plugins that do that and with WP Cerber (not in the directory anymore, I think) there is also an implementation for plugins.

What do you think?

[roytanck]

Thanks for this suggestion. I'll have to look into this when I have more time, but at first glance it does sound like an interesting new feature.