Download manifest for current Expo SDK and add commands to switch versions

[byCedric]

Description of the feature

Would be good if we can match the manifest version with the Expo SDK.

Would also be nice if we can add commands to switch between SDK versions, e.g.

• Use schema from project SDK version
• Use schema from different SDK version ...

Motivation

If you run an older SDK version, the manifest validation/autocompletion should match this too. 😄 When we have this correlation, we can also implement deprecated properties and warn for those being used.