Allow logged account to add other users as friends

[TheYuriG]

Housekeeping job for pending requests.
Requested by chaZmich on Jan 19th, 2022, here.

Reason: Allows tracking for players that don't have their trophies set to public, without making them do so.

Reference: Send Friend Request, Accept Friend Request.

We already have a method to retrieve the friends list, so it's probably good to use that before trying to add/accept friend requests.