Add support for v0.11 GRPC services

This also refactors the client GRPC wrapper to dynamically load the
request objects.
All GRPC generated client files now live under lib/grpc_services

lib/grpc_services/chainrpc/chainnotifier_services_pb.rb

@@ -0,0 +1,51 @@
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# Source: chainrpc/chainnotifier.proto for package 'chainrpc'
+
+require 'grpc'
+require 'chainrpc/chainnotifier_pb'
+
+module Chainrpc
+  module ChainNotifier
+    # ChainNotifier is a service that can be used to get information about the
+    # chain backend by registering notifiers for chain events.
+    class Service
+
+      include GRPC::GenericService
+
+      self.marshal_class_method = :encode
+      self.unmarshal_class_method = :decode
+      self.service_name = 'chainrpc.ChainNotifier'
+
+      #
+      # RegisterConfirmationsNtfn is a synchronous response-streaming RPC that
+      # registers an intent for a client to be notified once a confirmation request
+      # has reached its required number of confirmations on-chain.
+      #
+      # A client can specify whether the confirmation request should be for a
+      # particular transaction by its hash or for an output script by specifying a
+      # zero hash.
+      rpc :RegisterConfirmationsNtfn, ConfRequest, stream(ConfEvent)
+      #
+      # RegisterSpendNtfn is a synchronous response-streaming RPC that registers an
+      # intent for a client to be notification once a spend request has been spent
+      # by a transaction that has confirmed on-chain.
+      #
+      # A client can specify whether the spend request should be for a particular
+      # outpoint  or for an output script by specifying a zero outpoint.
+      rpc :RegisterSpendNtfn, SpendRequest, stream(SpendEvent)
+      #
+      # RegisterBlockEpochNtfn is a synchronous response-streaming RPC that
+      # registers an intent for a client to be notified of blocks in the chain. The
+      # stream will return a hash and height tuple of a block for each new/stale
+      # block in the chain. It is the client's responsibility to determine whether
+      # the tuple returned is for a new or stale block in the chain.
+      #
+      # A client can also request a historical backlog of blocks from a particular
+      # point. This allows clients to be idempotent by ensuring that they do not
+      # missing processing a single block within the chain.
+      rpc :RegisterBlockEpochNtfn, BlockEpoch, stream(BlockEpoch)
+    end
+
+    Stub = Service.rpc_stub_class
+  end
+end