Implement upgrade checker utility

The MySQL Shell utility has a contains am "Upgrade Checker Utility" starting with MySQL 8.0.13:

7.1 Upgrade Checker Utility
The util.checkForServerUpgrade() function is an upgrade checker utility that enables you to verify whether MySQL server instances are ready for upgrade. From MySQL Shell 8.0.13, you can select a target MySQL Server release to which you plan to upgrade, ranging from the first MySQL Server 8.0 General Availability (GA) release (8.0.11), up to the MySQL Server release number that matches the current MySQL Shell release number. The upgrade checker utility carries out the automated checks that are relevant for the specified target release, and advises you of further relevant checks that you should make manually.

You can use the upgrade checker utility to check MySQL 5.7 server instances for compatibility errors and issues for upgrading. From MySQL Shell 8.0.13, you can also use it to check MySQL 8.0 server instances at another GA status release within the MySQL 8.0 release series. If you invoke checkForServerUpgrade() without specifying a MySQL Server instance, the instance currently connected to the global session is checked. To see the currently connected instance, issue the \status command.

https://dev.mysql.com/doc/mysql-shell/8.0/en/mysql-shell-utilities-upgrade.html

Some users would like MariaDB to also have an upgrade checker utility that could determine whether an existing MariaDB or MySQL server is compatible with an upgrade to a specific MariaDB version.