[REQUIREMENT][Ruby Client] Add API of Getting Supported Language Tag List

[InaSong]

Is your feature request related to a problem? Please describe. No support for API "Get the supported language tag list of the configured product"

Describe the solution you'd like Add the support of Singleton API for getting the supported language tag list of the configured product

[Xiaochao8]

There is not this requirement for now, so mark it as low priority.