Returns true if the given user has at least one active membership for a paid membership level.
- $user_id (int) - ID of the user account to check. Default is the ID of the currently logged-in user.
trueif the user has an active, paid membership or if the user has a canceled membership that has not yet expired.
falseif the user has no membership at all, or only has a free membership, or has an expired/canceled/pending membership.