Add dry-run apps deployment

[nicoloboschi]

Fixes #532

Changes:

• New option in the deploy langstream apps deploy --dry-run my-app -app .... This sends a request to the control plane.
• The control plane handles the new option and generates the application description with the resolved application. The app is not deployed
• You can customize the output with -o yaml/json. By default is yaml
• The same option is not recognized for the update command since we don't want to expose already stored secrets to the user (that might not have access to them)

[eolivelli]

Great work

Can you please add this option also in the "docker run" mode ?
People that are used to use "docker run" don't have a control plane running

[eolivelli]

LGTM as far as we add support for "docker run" users.

I don't want to block the PR