Add the domain DNS refresh request time field to the DB schema (#1280)

* Add the domain DNS refresh request time field to the DB schema

This isn't used yet, but it will eventually be the replacement for the dns-pull
task queue once we get further in the migration.

* Remove index

db/src/main/resources/sql/flyway/V101__domain_add_dns_refresh_request_time.sql

@@ -0,0 +1,21 @@
+-- Copyright 2021 The Nomulus Authors. All Rights Reserved.
+--
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+--
+--     http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+
+alter table "Domain"
+    add column if not exists "dns_refresh_request_time" timestamptz;
+
+alter table "DomainHistory"
+    add column if not exists "dns_refresh_request_time" timestamptz;
+
+create index domain_dns_refresh_request_time_idx on "Domain" (dns_refresh_request_time);