Add 3 more SQL indexes to the Host table (#1559)

* Add 3 more SQL indexes to the Host table

These indexes on creationTime, deletionTime, and currentSponsorRegistrarId are
present on the other two EPP resource tables (Domain and Contact), and are
useful for a wide variety of operations/analytics queries.

db/src/main/resources/sql/flyway/V113__add_host_missing_indexes.sql

@@ -0,0 +1,18 @@
+-- Copyright 2022 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.
+
+CREATE INDEX IDXy98mebut8ix1v07fjxxdkqcx ON "Host" (creation_time);
+CREATE INDEX IDXovmntef6l45tw2bsfl56tcugx ON "Host" (deletion_time);
+CREATE INDEX IDXl49vydnq0h5j1piefwjy4i8er ON "Host" (current_sponsor_registrar_id);
+