Lighthouse - Performance Tuning WordPress Plugin 4.4.0

* FEATURE: Add CWV/RUM monitoring
* FEATURE: Add more security headers
* PERFORMANCE: Improve SpeedFactor cURL/CRON performance
* SECURITY: Improve XML RPC blocking

* FIX: Remove db_server_info() method for WordPress 4.9+ and ClassicPress compatibility
* FEATURE: Add automatic background updater

* FIX: Exclude mailto and tel links from prefetching
* FIX: Sanitize query string parameter for SQL injection check
* FIX: Remove unused variable
* UPDATE: Update PHP recommendations
* UPDATE: Update WordPress recommendations
* UPDATE: Update WordPress compatibility
* FEATURE: Add page caching (browser caching)
* FEATURE: Add support for Cloudflare page caching headers

* FIX: Update User Agent check to prevent PHP 8+ warnings
* UPDATE: Update ClassicPress recommendations
* UPDATE: Remove all "Beta" labels
* UPDATE: Refactor code (WPCS)

* UPDATE: Only load ChartJS on Lighthouse pages to prevent conflicts with other getButterfly plugins

* UPDATE: Updated Thin UI to latest version (2.1.1)

* UPDATE: Removed Core Web Vitals and CrUX
* UPDATE: Added option to delete old settings, tables, files and logs on-demand
* UPDATE: Added option to remove the Custom Fields metabox from the post editor because it uses a very slow meta_key sort query

* FIX: Fixed update checker loop
* UPDATE: Removed CrUX report

* UPDATE: Refactored registration spam prevention to shortcircuit the `register_post` hook
* UPDATE: Refactored the blacklist log into an option counter
* UPDATE: Deprecated Core Web Vitals and CrUX
* UPDATE: Updated WordPress recommendation
* UPDATE: Updated ClassicPress recommendation

* FIX: Fixed undefined queries in WordPress back-end
* SECURITY: Add failed login count
* SECURITY: Refactor Dashboard cards and add a Security card