Remove 'fullyQualified' from host and domain names (#631)

* Remove 'fullyQualified' from host and domain names

We don't actually enforce that these are properly fully-qualified
(there's no dot at the end) and we specifically use the term "label
name" when talking about labels.

Note: this doesn't convert FQDN -> DN (et al) in at least two types of
cases:
1. When the term is part of the XML schema
2. When the term is used by some external system, e.g. SafeBrowsing API

* Add TODO to rename fields

db/src/main/resources/sql/flyway/V34__rename_fully_qualified_names.sql

@@ -0,0 +1,17 @@
+-- Copyright 2020 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" RENAME COLUMN "fully_qualified_domain_name" TO "domain_name";
+ALTER TABLE "HostResource" RENAME COLUMN "fully_qualified_host_name" TO "host_name";
+ALTER TABLE "HostHistory" RENAME COLUMN "fully_qualified_host_name" TO "host_name";