从Serein.Library分离了WebSocket/Modbus；新增了Json门户类，用于未来的Http、WebSocket、Mqtt、gRPC、QUIC扩展。

Serein.Proto.Modbus/ModbusFunctionCode.cs

@@ -0,0 +1,41 @@
+namespace Serein.Proto.Modbus
+{
+    /// <summary>
+    /// Modbus 功能码枚举
+    /// </summary>
+    public enum ModbusFunctionCode
+    {
+        /// <summary>
+        /// 读线圈
+        /// </summary>
+        ReadCoils = 0x01,
+        /// <summary>
+        /// 读离散输入
+        /// </summary>
+        ReadDiscreteInputs = 0x02,
+        /// <summary>
+        /// 读保持寄存器
+        /// </summary>
+        ReadHoldingRegisters = 0x03,
+        /// <summary>
+        /// 读输入寄存器
+        /// </summary>
+        ReadInputRegisters = 0x04,
+        /// <summary>
+        /// 写单个线圈
+        /// </summary>
+        WriteSingleCoil = 0x05,
+        /// <summary>
+        /// 写单个寄存器
+        /// </summary>
+        WriteSingleRegister = 0x06,
+        /// <summary>
+        /// 写多个线圈
+        /// </summary>
+        WriteMultipleCoils = 0x0F,
+        /// <summary>
+        /// 写多个寄存器
+        /// </summary>
+        WriteMultipleRegister = 0x10,
+    }
+}