[Feature][Manager] Support field description when parsing field by JSON

[featzhang]

Description

The current JSON format can not specify field comments:

[
  { "fid": "int"  },
  { "ftitle": "string"  },
  { "fcontent": "string"  },
  { "fcreates_time": "timestamp"  }
]

Change the format of JSON to the following format:

[
  {
    "name": "fid",
    "type": "int",
    "desc": "news id"
  },
  {
    "name": "ftitle",
    "type": "string",
    "desc": "news title"
  },
  {
    "name": "fcontent",
    "type": "string",
    "desc": "news content"
  },
  {
    "name": "fcreates_time",
    "type": "timestamp",
    "desc": "news created time, in format 'yyyy-MM-dd HH:mm:ss'"
  }

Use case

No response

Are you willing to submit PR?

• Yes, I am willing to submit a PR!

Code of Conduct

• I agree to follow this project's Code of Conduct