Extend tuist generate command to take -scheme as parameter to include all targets from specified scheme

[shahzadmajeed]

What happened?

As per discussion here https://tuistapp.slack.com/archives/C018QG7U7SN/p1668035683047669, it would be a great addition to Tuist if we can generate a focused project from a scheme. This will give developers control over what they want to include in generated project. Currently, you have to specify all targets while generating a focused project which is prone to errors and contextual mistakes.

Proposal (thanks to Daniele Formichelli for the suggestion):
Add a -scheme parameter to tuist generate command so that we focus on the targets specified in scheme i.e tuist generate --scheme scheme_name

Additional:
Additionally, a slightly related work was requested in a separate issue #4837 to allow specifying external targets in schemes. If this is not too much work then it would be ideal to include this work in pull request implementing above proposal.

[github-actions]

Hola 👋,

We want to inform you that the issue has been marked as stale. This means that there hasn't been any activity or updates on it for quite some time, and it's possible that it may no longer be relevant or actionable.
If you still believe that this issue is valid and requires attention, please provide an update or any additional information that can help us address it. Otherwise, we may consider closing it in the near future.
Thank you for your understanding.

[github-actions]

Hola 👋,

We want to inform you that we have decided to close this stale issue as there hasn't been any activity or response regarding it after marking it as stale.

We understand that circumstances may have changed or priorities may have shifted, and that's completely understandable. If you still believe that this issue needs to be addressed, please feel free to reopen it and provide any necessary updates or additional information.

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