Add ClientOptions in constructor for grpc-js clients

[RMHonor]

The @grpc/grpc-js has types for the options in client constructors, this template change conditionally adds these types to generated constructors.

[agreatfool]

I found a strange issue.

See the client codes in example:

const BookServiceClient = grpc.makeClientConstructor(bookGrpcPb["com.book.BookService"], "BookService");
const client = new BookServiceClient("127.0.0.1:50051", grpc.credentials.createInsecure()) as any as bookGrpcPb.BookServiceClient;

Client class BookServiceClient comes from makeClientConstructor, which is:

export function makeClientConstructor(
  methods: ServiceDefinition,
  serviceName: string,
  classOptions?: {}
): ServiceClientConstructor {

  class ServiceClientImpl extends Client implements ServiceClient {
  }

  // ...

  return ServiceClientImpl;
}

See, the return type of function makeClientConstructor is ServiceClientConstructor, which is:

export interface ServiceClientConstructor {
  new (
    address: string,
    credentials: ChannelCredentials,
    options?: Partial<ChannelOptions>
  ): ServiceClient;
  service: ServiceDefinition;
}

Type of options here is ChannelOptions.

But, actually in the source codes, which really returned from function makeClientConstructor is class ServiceClientImpl who extends Client, and see here:

export class Client {

  constructor(
    address: string,
    credentials: ChannelCredentials,
    options: ClientOptions = {}
  ) {
    //...
  }
  //...
}

Type of options here is ClientOptions. Which is:

export type ClientOptions = Partial<ChannelOptions> & {
  channelOverride?: Channel;
  channelFactoryOverride?: (
    address: string,
    credentials: ChannelCredentials,
    options: ClientOptions
  ) => Channel;
  interceptors?: Interceptor[];
  interceptor_providers?: InterceptorProvider[];
  callInvocationTransformer?: CallInvocationTransformer;
};

They are not consistent.

[agreatfool]

And since the returned object is class ServiceClientImpl and which extends class Client, I think your pr shall be OK.