request: update `Args` to support Chat Input commands

[favna]

Is there an existing issue or pull request for this?

• I have searched the existing issues and pull requests

Feature description

When we first wrote Sapphire we added support for Arguments for message-based commands, however, they were never updated for Chat Input commands in version 3 as we had to cut it in order to be able to ship v3 sooner. That means it is moved to the scope of v4 and this issue is to track this feature.

Desired solution

Arguments has to be updated to support Chat Input commands

Alternatives considered

• Only using the resolvers for Chat Input commands. As resolvers already make the backbone of Arguments and Chat Input command arguments are only really relevant for String type Chat Input commands the string content could easily be parsed by resolvers.
  • This is a valid argument, however supporting Arguments will allow more syntactic sugar and allow for less code to achieve the same.,

Additional context

No response