Dynamic command options with autocomplete

[Rodentman87]

Now that autocomplete is happening, it would be nice to be able to also return an extra set of options for users to fill out. This could be useful for a custom command system where users can make a custom command that takes arguments, or it could also be used for something like a settings command where an autocomplete can be used to let the user select the option, then the type for the value could be dynamically filled in. This could be something along the lines of

{
  type: 8,
  data: {
    choices: [
      {
        name: 'A user visible choice display name',
        value: 'a_user_invisible_choice_value',
        options: [/* array of dynamic options */]
      }
    ]
  },
}

These dynamic extra options could even be rendered as the user hovers an option:

Then the extra options would be passed to the client just like normal command options.