[BUG] [Singleton Service] Wrong localeID display when combination is valid while the pattern result is from different locale

[nannany00]

Describe the bug
Currently, Singleton Service below APIs, provides the pattern data for "dates, numbers, currencies, plurals, measurements, dateFields":
When combination of language and region is valid,
"dates, numbers, currencies, measurements" following the valid combined locale; however,
"plurals,dateFields" always following language.
GET /i18n/api/v2/formatting/patterns Get pattern from CLDR
POST /i18n/api/v2/combination/translationsAndPattern Get translations and patterns

Therefore, it will be different localeID when to get the pattern for "dates,plurals" etc.
so Singleton should return "" for this scenario.

To Reproduce
Steps to reproduce the behavior:

1. Start the latest Singleton Service build
2. Find the APIs to get pattern by language and region
3. Check the Response body
4. Example data:
   language: es
   region: US
   scope: dates,dateFields
   in Response:

"data": {
    "localeID": "es-US",
    "language": "es",
    "region": "US",
....

Expected behavior
"localeID" should be "", as "dates" is from "es-US", "dateFields" is from "es".

Screenshots
NA

Desktop (please complete the following information):
NA

Additional context
NA

[nannany00]

The "localeID" always display as the combined locale even if just request "plurals" or "dateFields".