[cmd] Add withRequirements decorator

[TheComputer314]

Small decorator to slightly simplify command compositions that modify subsystem requirements.

TODO:

• C++
• Unit tests

[github-actions]

This PR modifies commands. Please open a corresponding PR in Python Commands and include a link to this PR.

[KangarooKoala]

Small decorator to slightly simplify command compositions that modify subsystem requirements.

I don't entirely follow- Could you provide an example of when this might be used? /cur

[TheComputer314]

public class Superstructure extends SubsystemBase {
  private Command expose(Command internal) {
    var proxied = internal.asProxy();
    proxied.addRequirements(this);
    return proxied;
  }
}

The above can be simplified to:

public class Superstructure extends SubsystemBase {
  private Command expose(Command internal) {
    return internal.withRequirements(this);
  }
}

Oblarg posted a similar class in the Discord as a way to manage nested Subsystems, but it used a .withRequirements() decorator that didn't exist yet.

I know it's a niche decorator with niche use cases, but it's pretty simple to add.

[KangarooKoala]

Makes sense!