Site Health: Improve the error message displayed when activating a plugin that...

Site Health: Improve the error message displayed when activating a plugin that requires a higher version of PHP or WordPress.

This adds some extra details to the message:

* The current PHP or WordPress version.
* The plugin's minimum required PHP or WordPress version.
* A link to the support documentation on how to update PHP.

Props stuffradio, johnbillion, garrett-eclipse, sabernhardt, williampatton, SergeyBiryukov.
Fixes #48245.
Built from https://develop.svn.wordpress.org/trunk@48172


git-svn-id: https://core.svn.wordpress.org/trunk@47941 1a063a9b-81f0-0310-95a4-ce76da25c4cd