AtatCmd parameters as consts

[MathiasKoch]

The below parameters of atatCmd could be written as eg const CAN_ABORT: bool = false;

    /// Whether or not this command can be aborted.
    fn can_abort(&self) -> bool {
        false
    }

    /// The max timeout in milliseconds.
    fn max_timeout_ms(&self) -> u32 {
        1000
    }

    /// Force the ingress manager into receive state immediately after sending
    /// the command.
    fn force_receive_state(&self) -> bool {
        false
    }

    /// Force client to look for a response.
    /// Empty slice is then passed to parse by client.
    /// Implemented to enhance expandability fo ATAT
    fn expects_response_code(&self) -> bool {
        true
    }