Consolidate "Delete package" modals into a shared component.

thought: The modals in app/assets/javascripts/packages_and_registries/package_registry/components/list/packages_list.vue and app/assets/javascripts/packages_and_registries/infrastructure_registry/list/components/packages_list.vue are quite similar. It would be nice to consolidate them into a single shared component. No need to address this now though, this would warrant a follow-up.