Automatically get buffer len in MqttClient

src/client/client.rs

@@ -47,11 +47,12 @@ where
     pub fn new(
         network_driver: T,
         buffer: &'a mut [u8],
-        buffer_len: usize,
         recv_buffer: &'a mut [u8],
-        recv_buffer_len: usize,
         config: ClientConfig<'a, MAX_PROPERTIES, R>,
     ) -> Self {
+        let buffer_len = buffer.len();
+        let recv_buffer_len = recv_buffer.len();
+
         Self {
             raw: RawMqttClient::new(
                 network_driver,