[BUG] [GO service]Return to 400 when inputting language-region as locale in GET /formatting/number/localizedNumber API.

[lyiyu66]

Describe the bug
commit: 3c64756

To Reproduce
Steps to reproduce the behavior:

1. Go to 'GET
   /formatting/number/localizedNumber' API.
2. Input "en-US" and "5.01" as locale and number parameters' values.
3. See error

{
  "response": {
    "code": 400,
    "message": "invalid Locale 'en-US'"
  }
}

Expected behavior
Return to 200 and correct number format:

{
  "response": {
    "code": 200,
    "message": "OK",
    "serverTime": ""
  },
  "signature": "",
  "data": {
    "number": "5.01",
    "formattedNumber": "5",
    "scale": "0",
    "locale": "en-US"
  }
}