refactor: remove hash resolver proto definition

This removes the hash resolver proto definition and related code ahead
of replacing it with an http endpoint that will accept resolve requests
in the format currently used by Raiden.

lib/grpc/GrpcServer.ts

@@ -9,7 +9,6 @@ import errors from './errors';
 import { XudService } from '../proto/xudrpc_grpc_pb';
 import { promises as fs } from 'fs';
 import serverProxy from './serverProxy';
-import { HashResolverService } from '../proto/hash_resolver_grpc_pb';
 
 class GrpcServer {
   private server: any;
@@ -44,10 +43,6 @@ class GrpcServer {
       subscribeSwaps: grpcService.subscribeSwaps,
     });
 
-    this.server.addService(HashResolverService, {
-      resolveHash: grpcService.resolveHash,
-    });
-
     this.grpcService = grpcService;
 
     this.server.use((ctx: any, next: any) => {

lib/grpc/GrpcService.ts

@@ -11,7 +11,6 @@ import { errorCodes as lndErrorCodes } from '../lndclient/errors';
 import { LndInfo } from '../lndclient/LndClient';
 import { SwapSuccess, SwapFailure } from '../swaps/types';
 import { SwapFailureReason } from '../constants/enums';
-import { ResolveRequest, ResolveResponse } from '../proto/hash_resolver_pb';
 
 /**
  * Creates an xudrpc Order message from an [[Order]].
@@ -316,7 +315,6 @@ class GrpcService {
             break;
           case SwapFailureReason.InvalidSwapRequest:
           case SwapFailureReason.PaymentHashReuse:
-          case SwapFailureReason.InvalidResolveRequest:
             // these cases suggest something went very wrong with our swap request
             code = status.INTERNAL;
             break;
@@ -571,22 +569,6 @@ class GrpcService {
     }
   }
 
-  /*
-   * Resolving LND hash. See [[Service.resolveHash]]
-   */
-  public resolveHash: grpc.handleUnaryCall<ResolveRequest, ResolveResponse> = async (call, callback) => {
-    try {
-      const resolveResponse = await this.service.resolveHash(call.request);
-      const response = new ResolveResponse();
-      if (resolveResponse) {
-        response.setPreimage(resolveResponse);
-      }
-      callback(null, response);
-    } catch (err) {
-      callback(this.getGrpcError(err), null);
-    }
-  }
-
   public shutdown: grpc.handleUnaryCall<xudrpc.ShutdownRequest, xudrpc.ShutdownResponse> = (_, callback) => {
     try {
       this.service.shutdown();