Better lint package YML files

[alexevanczuk]

This PR updates the behavior for bin/packs lint_package_yml_files to do some extra linting:

1. It now moves metadata.owner (if it exists) to the top-level owner key.
2. It sorts top-level keys based on an opinionated/preferred order.

Note that I made a change to parse_packwerk so that now use_packs uses most of the same listing rules as parse_packwerk. That is – lint_package_yml_files isn't doing much since write_package_yml file already does most of the linting work. We might even consider moving the rest of the linting rules that are still in use_packs into write_package_yml!