Remove NBI package global services and refactor NBI servers

controller/api/initialise_test.go

controller/controller.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/core.go

controller/northbound/server/core_test.go

controller/northbound/server/csbi.go

controller/northbound/server/nbi.go

controller/northbound/server/pnd.go

controller/northbound/server/pnd_test.go

controller/northbound/server/role.go

controller/northbound/server/role_test.go

controller/northbound/server/sbi.go

controller/northbound/server/test_util_test.go

controller/northbound/server/user.go

controller/northbound/server/user_test.go

controller/nucleus/memoryPndStore.go