Reports unnecessary `grpc` or standard `http[s]` schemes usage in gRPC requests

Example requests:

# `grpc` scheme may be omitted since insecure connection is assumed by default
GRPC grpc://localhost/TestService/testRpc

# `http` scheme may be omitted: prefer empty scheme for insecure connection and a dedicated `grpcs` scheme for a secure one
GRPC http://localhost/TestService/testRpc

# `https` scheme should be replaced by `grpcs`: prefer a dedicated `grpcs` scheme to indicate that transport layer security should be enabled to execute the request
GRPC https://localhost/TestService/testRpc

To avoid confusion, it is recommended to use dedicated `grpcs` scheme in a gRPC request, when the request should use secure channel underneath. Otherwise, the scheme might be completely omitted