get_debug_type() does the same thing but better (spelling type names
in the same way as in type declarations, and including names of
object classes and resource types). It was added in PHP 8, but the
symfony/polyfill-php80 package provides it while we still support 7.4.
Also remove uses of get_class() and get_resource_type() where the new
method already provides the same information.
For reference:
https://www.php.net/manual/en/function.get-debug-type.phphttps://www.php.net/manual/en/function.gettype.php
To keep this safe and simple to review, I'm only changing cases where
the type is immediately used in an exception message.
Change-Id: I325efcddcb58be63b1592b9c20ac0845393c15e2
