Add Kernel API for WebSocket message broadcast

[Zuoqiu-Yingyi]

• Please commit to the dev branch
• For contributing new features, please supplement and improve the corresponding user guide documents
• For bug fixes, please describe the problem and solution via code comments
• For text improvements (such as typos and wording adjustments), please submit directly

Add APIs for message broadcast

Tested on Windows 11

• /ws/broadcast: WebSocket
  • Push broadcast messages
  • Receive broadcast messages
  • query params
    • channel: broadcast channel name
  • example
    • ws://127.0.0.1:6806/ws/broadcast?channel=your-channel-name
• /api/broadcast/channels: GET request
  • Get all channels' info
  • response body

    • {
          "code": 0,
          "msg": "",
          "data": {
              "channels": [
                  {
                      "name": "test-channel",
                      "count": 1
                  }
              ]
          }
      }

• /api/broadcast/postMessage: POST request
  • Push broadcast messages
  • request body

    • {
          "channel": "your-channel-name",
          "message": "your-message-content"
      }

      • channel: the name of channel
      • message: the message will be broadcast
  • response body

    • {
          "code": 0,
          "msg": "",
          "data": {
              "channel": {
                  "name": "your-channel-name",
                  "count": 1
              }
          }
      }

      • data.channel.count: the count of channel listener

    • {
          "code": -1,
          "msg": "broadcast channel [your-channel-name] not found",
          "data": null
      }

    • {
          "code": -2,
          "msg": "broadcast message failed: ...",
          "data": null
      }

• /api/broadcast/getChannelInfo: POST request
  • get the info of a channel
  • request body

    • {
          "name": "your-channel-name"
      }

      • name: the name of channel
  • response body

    • {
          "code": 0,
          "msg": "",
          "data": {
              "channel": {
                  "name": "your-channel-name",
                  "count": 1
              }
          }
      }

      • data.channel.name: the name of channel
      • data.channel.count: the count of channel listener

    • {
          "code": -1,
          "msg": "broadcast channel [your-channel-name] not found",
          "data": null
      }