add enforce_architecture flag wherever enforce_privacy is used

[schoblaska]

The packs half of rubyatscale/parse_packwerk#39.

This PR adds an enforce_architecture flag wherever enforce_privacy is used, bringing parity between the two extensions for packs functionality (namely, setting these flags in package.yml files when packs are created or moved).

[schoblaska]

$ packs create --no-enforce-architecture packs/foo
$ cat packs/foo/package.yml
enforce_dependencies: true
enforce_privacy: true
enforce_architecture: false
owner: MyTeam # specify your team here, or delete this key if this package is not owned by one team

$ packs create packs/bar
$ cat packs/bar/package.yml
enforce_dependencies: true
enforce_privacy: true
enforce_architecture: true
owner: MyTeam # specify your team here, or delete this key if this package is not owned by one team