Build & Deploy should be available as distinct CLI commands

[meryllblanchet]

Is your feature request related to a problem? Please describe.
As of today, aio app deploy builds and deploys the whole app.
aio app deploy --skip-build only deploys the app.
aio app deploy --skip-deploy only builds the app.

This is confusing for users and we should provide a more obvious way to handle build and deploy separately. This can be very useful for CI/CD and other automation use-cases.

Describe the solution you'd like
Proposal:

aio app build builds the whole app
aio app build -a|--action=action builds an action
aio app build --all-actions builds all actions
aio app build -s|--static builds the SPA

aio app deploy behaves as of today if there's no build.
aio app deploy just deploys if there's a build.
aio app deploy -b|--build forces the build before the deploy (do we even need more fine-grained based?)

[aiojbot]

JIRA issue created: https://jira.corp.adobe.com/browse/ACNA-906

[meryllblanchet]

@Himavanth @purplecabbage let's also consider the aio app run command and its flags.

[Himavanth]

Need to also consider multi-package manifests. (especially the --action flag)