Improve UX for UsePackwerk.move_to_parent!

[alexevanczuk]

Summary

I ran an experiment in ZP to nest a pack.

Here's friction I discovered, with a

• ✅sorbet/config ignores a lot of spec files. We might want to auto-migrate those ignores for users.
• A lot of package.yml files will reference the old packs in their dependencies. This led to two pieces of friction:
  • According to the validation, we must actually remove these, because nothing should depend on child packs. I think we should REMOVE this validation until there is an easier way to promote a child pack's public API to the parent pack. Otherwise, there is a huge barrier of entry for nested packs where folks will have to migrate all of their child packs public API to the parent pack. This validation lives in ZP right now so will be changed there.
  • ✅ This requires changing the name of the packs in each parent pack. I think I should update move_to_parent to do this for the user since we have commands to rewrite package.yml files with a new list of dependencies.
• .rubocop.yml is hard-coded to packs/*/app/... type paths, so I needed to expand this. This configuration lives in ZP, so I changed it there.

Commits

• add failing test
• fix failing test
• add other failing test
• fix spec
• bump version