@type t() :: %KNXex.GroupAddressServer.GroupAddressData{
  address: KNXex.GroupAddress.t(),
  last_update: DateTime.t() | nil,
  name: String.t() | nil,
  type: {name :: String.t(), type :: String.t()},
  value: term() | nil
}

Represents the KNX group address, that is used in this server.

In addition to KNXex.GroupAddress.t(), the name, last update time and value are stored. If the value is nil, the value is not known (has not been hydrated or received from the KNX bus yet).

Type is a tuple of name and type, i.e. {"DPT_Switch", "1.001"}.