A single network firewall rule (allow or deny).
@type action() :: :allow | :deny
@type direction() :: :ingress | :egress
@type t() :: %Miosa.Types.NetworkPolicyRule{ action: action(), direction: direction(), host: String.t() | nil, port: String.t() | pos_integer() | nil, protocol: String.t() | nil }
@spec from_map(map()) :: t()