Implement API-validations to recommend user to update the app, if there is a newer version available in PlayStore/AppleStore

Instead of an additional API to check the app-version, all APIs are now expected to receive appType (iOS/Android) and app-version in the request PayLoad. If it is an older version, the API isn't processed but throws an error. Else, API is processed.

Saved the app from making additional/trivial APIs.