[FEATURE]: service_http_server support OLTP log input

[messixukejia]

service_http_server 支持OTLP log输入。目前已支持sls、prometheus、influxdb等。

OTLP log采集配置：

{
    "inputs":
    [
      {
        "detail": {
            "Format": "otlplog",
            "Address": "http://127.0.0.1:12345/v1/logs"
        },
        "type": "service_http_server"
      }
    ],
    "flushers" : [
      {
        "type" : "flusher_stdout",
        "detail" : {
          "OnlyStdout": true
        }
      }
    ]
  }

实现机制

外部输入：OTLP v1 log 内部处理流：SLS PB