Merge topic 'find_package-refactor-path-generation'

2f69c0233c cmFindPackageCommand: Optimize the last calls to `TryGeneratedPaths`
076a4b44b0 cmFindPackageCommand: Path generators are actually reusable
664abd486f cmFindPackageCommand: Better names for template parameters
c862797a40 cmFindPackageCommand: Rename some generators
fdd14b1744 cmFindPackageCommand: Deduplicate directory listing code
08e7fb3cfa cmFindPackageCommand: Compile-time path generator expressions
61eb5d4de5 cmFindPackageCommand: Avoid friendship between command class and generator
ef62f213f8 cmFindPackageCommand: Drop dead code
...

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !7445