feat(cli): Restore packages from webcs

[theduke]

Allow "package unpack" to restore packages

Add a new --format option to package unpack.

• package: Try to restore a usable package dir with a wasmer.toml
• webc: just unpack the webc

Also adds a new wasmer-package crate that can hold package related functionality.

As a drive-by chore, also lifts pretty_assertions to be a workspace dependency.

Closes #5085

[maminrayej]

Otherwise LGTM.