Struct representing the state of RTSP session
@type auth_t() :: nil | :basic | {:digest, digest_opts()}
@type digest_opts() :: %{realm: String.t() | nil, nonce: String.t() | nil}
@type t() :: %Membrane.RTSP.Logic.State{ auth: auth_t(), cseq: non_neg_integer(), execution_options: Keyword.t(), session_id: binary() | nil, transport: any(), transport_module: term(), uri: URI.t() }