feat: support RunCloud Hub auto purge cache in the cache control

All Submissions:

[x] Have you followed the MainWP Contributing guideline?
[x] Does your code follow the WordPress' coding standards?
[x] Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Changes proposed in this Pull Request:

This change is to support RunCloud Hub in the Cache Control extension.

RunCloud Hub is server-side caching system that is provided by RunCloud for the users to make it easily to enable server-side page caching, where user can choose FastCGI Page Cache or Redis Full-Page Cache for NGINX servers.

The RunCloud Hub WordPress plugin does more than cache purger, where it has more cache rule exclusion, preload, etc.

It also support some popular cache plugins, user can combine RunCloud Hub (server-side) with WP Rocket, WP Super Cache, W3 Total Cache, etc (WordPress-side).

This is also the reason to put RunCloud Hub on the latest list of cache plugin detection on the check_cache_solution function. This is to make sure when user use any other cache plugin, it will always be detected as RunCloud Hub. And then when clearing cache of RunCloud Hub, it will also clear the cache of the other plugin that user use.

How to test the changes in this Pull Request:

If you use RunCloud, you can enable RunCloud Hub feature in the RunCloud, then test Cache Control extension
if needed, we can provide test site with RunCloud Hub installed

Other information:

[x] Have you added an explanation of what your changes do and why you'd like us to include them?
[ ] Have you written new tests for your changes, as applicable?
[x] Have you successfully run tests with your changes locally?

Changelog entry

Added: RunCloud Hub to the Purge Cache system for the Cache-Control Extension

mainwp / mainwp-child