Specify which optional dependencies to install

[mattfarina]

Currently, optional dependencies are installed as a group when in non-interactive mode. There is a request to be able to specify which of the optional ones to install. This would impact the CLI and the Go API.

The CLI would need a flag to take a list of optional dependency names.

The API would need a method to take a list of optional dependencies to install.

[mattfarina]

Some additional details:

• We use names unless an alias is present. When the alias is present use that instead
• Linting should make sure the name (alias or name) is unique
• The names passed in are the alias or name (in case of no alias)