Build Process for Manual deployment of Amplify Console

**Is your feature request related to a problem? Please describe.**
As a developer, I want to trigger build when I manually deploy so that I can ship my application withiout Git provider.

**Describe the solution you'd like**
Add an option to build frontend or backend in a manual deployment app, and manual deployment should run settled build process.

**Additional context**
I heard from developers that they needed to use Amplify without Git provider because of the following three reasons:

- Required highly secured development environment
- Cost
- Less time for POC

But, it seems that currently manual deployment feature only allows us to deploy the built artifact, and build process does not run on Amplify.
Thus, they cannot set build process without git provider and hard to use Amplify for their development.

No files, tests, or entry points are named. Start by reviewing the manual deployment flow and its current built-artifact boundary, then define how frontend and backend builds should be configured and what a successful build-and-deploy should produce.

Written by the indexing model from the issue text.