Add get_current_user helper func to fetch data about authenticated user without providing username or user_id

[artbarte]

No description provided.

[kanimaru]

Like the Idea but would not have an Idea what to use it for?

[artbarte]

I use it to retrieve the broadcaster ID and username for users I don't know in advance. This allows users to authenticate dynamically with their accounts and play my game without manually entering their username.