doc: metadata_expire is both [main] and per-repo option. (RhBug:1065728)
refactor: dnf.cli.commands.InstallCommand
api: Support filtering by repository name in Base.install.
Support filtering by repository name in install_groupie.
api: Support filtering by repository name in Base.select_group.
Support filtering by repository name in installPkgs.
Add repository-packages install command.

Related: RhBug:908764