This diff introduces refactoring the Tonic client utility function names for the Identity service in a Rust native library.
As we are using a single Rust library for the native which will contain clients and helper functions for all services we should refactor the Identity service-related function names to be more specific.
This refactoring adds an `identity` prefix to the function names.
Linear task: [[ https://linear.app/comm/issue/ENG-1333/implement-native-client-for-the-tunnelbroker-api-using-rust | ENG-1333 ]]