Plugin Directory: "Tested up to" version should include minor releases

[SergeyBiryukov]

[3493] added "tested up to" version to the new plugin directory, but it's not automatically adjusted for minor releases, like in the old directory.

• ​https://plugins.svn.wordpress.org/bbpress/tags/2.5.10/readme.txt says: "Tested up to: 4.5"
• ​https://wordpress.org/plugins/bbpress/ shows: "Compatible up to: 4.5.4"
• ​https://wordpress.org/plugins-wp/bbpress/ shows: "Tested up to: 4.5"

This was previously mentioned in comment:113:ticket:1719, but never addressed:

Heads up, Not all plugins specify a tested up to version, so this should be conditional, and it should also utilise the comparable versions from wporg_get_version_equivalents() (ie. tested up to 4.5, should show as 4.5.2)

[dd32]

In 4201:

Plugin Directory: Conditionally show the Tested up to: field based on whether the plugin has specified one, Automatically display the latest compatible minor release when appropriate.
For example, a plugin specifying Tested up to: 4.5.1 should automatically display Tested up to: 4.5.2 as appropriate.

Fixes #2093