Improvements for RBAC

cli/cmd/login.go

cli/cmd/logout.go

cli/cmd/userCreate.go

cli/cmd/userUpdate.go

controller/api/apiUtil_test.go

controller/api/auth_test.go

controller/api/initialise_test.go

controller/api/user_test.go

controller/cmd/root.go

controller/config/config.go

controller/configs/gosdn.toml

controller/controller.go

controller/interfaces/rbac/rbacService.go

controller/interfaces/rbac/user.go

controller/northbound/server/auth.go

controller/northbound/server/auth_interceptor.go

controller/northbound/server/auth_interceptor_test.go

controller/northbound/server/auth_test.go

controller/northbound/server/nbi.go

controller/northbound/server/pnd_test.go