Consolidate `amplify init --app` workflow

### Is this feature request related to a new or existing Amplify category?

_No response_

### Is this related to another service?

_No response_

### Describe the feature you'd like to request

When initializing a new Amplify project from an [existing project on GitHub](https://github.com/josefaidt/8414), we experience a workflow that is different from initializing a fresh project. Namely:

- local env created with name `sampledev`, whereas `amplify init -y` creates the `dev` environment
- Amplify CLI attempts to run `start` command after clone and initialization, which in a Next.js project (as an example) this command will fail without an existing build

### Describe the solution you'd like

- Amplify CLI creates default env "dev" as experienced with `amplify init -y`, or prompt for env name
- Amplify CLI does not run npm command `start` after clone and initialization
- Do not install project dependencies after clone, or allow developer to choose npm client (in this instance the Next.js project uses `pnpm` to manage dependencies but Amplify CLI installed using `yarn`, which creates an additional lockfile)

### Describe alternatives you've considered

Cloning and initializing manually

### Additional context

_No response_

### Is this something that you'd be interested in working on?

- [ ] 👋 I may be able to implement this feature request
- [ ] ⚠️ This feature might incur a breaking change