A user account under a merchant (id prefixed mem_).
mem_
@type status() :: :accepted | :pending | :expired | :disabled | :unknown
@type t() :: %Sumup.Member{ attributes: map() | nil, created_at: DateTime.t() | nil, id: String.t(), invite: map() | nil, metadata: map() | nil, permissions: [String.t()], raw: map(), roles: [String.t()], status: status(), updated_at: DateTime.t() | nil, user: map() | nil }