[Thinkit] Add mask known failures to test environment, Add protobuf overloads for methods storing test artifacts, Make ChassisName a string instead of string_view & Adding gNOI Certificate stub.

[Thinkit] Add mask known failures to test environment, Add protobuf overloads for methods storing test artifacts, Make ChassisName a string instead of string_view & Adding gNOI Certificate stub. #1878