Feature Request: Migration Command

**Is your feature request related to a problem? Please describe.**
It is easy to accidentally initialize an application as a Standalone Application when starting out with App Builder and applications of these types cannot be viewed in Adobe Experience Cloud.

**Describe the solution you'd like**
A new CLI command should be introduced to handle migrating between these two versions of applications. Suggestion: `aio app migrate`.

The command could inspect the user's working directory and generate a list of application types eligible for migration. For now, the only option would be to go from Standalone Application to DX Experience Cloud SPA v1.

**Describe alternatives you've considered**
The migration can be performed manually, but it is a tedious process, especially if the application has already been published. This will provide a huge QoL adjustment for users.