* finish ut for interceptor
* add client interceptor
* add server interceptor
* adjust location for test file
* format in goimports
* goimformat
* adjust package struct of grpc interceptor, move constant of grpc to common package.
* adjust gprc interceptor file struct
* refact directory, optimize grpc test case
* optimize proto
* delte test file
* delte test file
* fix npe for server integration
* go mod tidy
* remove duplicate constant