🥕[Improvement]: Enhance CLI to support @env() for enum options

### What happened?

When doing this in the CLI:

`dab init --config "dab-config.json" --host-mode "@env('mode')" `

I got this:

`Option 'host-mode' is defined with a bad format.`

It seems to me that validation is being done prematurely. av --v

### Version

Microsoft.DataApiBuilder 0.9.5-rc

### What database are you using?

Azure SQL

### What hosting model are you using?

Local (including CLI)

### Which API approach are you accessing DAB through?

REST, GraphQL

### Relevant log output

_No response_

### Code of Conduct

- [X] I agree to follow this project's Code of Conduct