Get account info of currently authenticated user

[apastel]

Opening an issue to track my forthcoming PR based on a previous discussion:

The account_menu endpoint returns accountName, channelHandle and accountPhoto, if that's what you're looking for. Should be possible to implement without much effort if you need it

https://music.youtube.com/youtubei/v1/account/account_menu

Originally posted by @sigma67 in #543 (comment)