Refactor ICANN reporting and billing into common package

This moves the default yearMonth logic into a common ReportingModule, rather than the coarse-scoped BackendModule, which may not want the default parameter extraction logic, as well as moving the 'yearMonth' parameter constant to the common package it's used in. This also provides a basis for future consolidation of the ReportingEmailUtils and BillingEmailUtils classes, which have modest overlap.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=183130311

java/google/registry/reporting/icann/sql/dns_counts.sql

@@ -0,0 +1,29 @@
+#standardSQL
+  -- Copyright 2017 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.
+
+  -- Query for DNS metrics.
+
+  -- You must configure this yourself to enable activity reporting, according
+  -- to whatever metrics your DNS provider makes available. We hope to make
+  -- this available in the open-source build in the near future.
+
+SELECT
+  STRING(NULL) AS tld,
+  metricName,
+  -1 AS count
+FROM ((
+  SELECT 'dns-udp-queries' AS metricName)
+  UNION ALL
+  (SELECT 'dns-tcp-queries' AS metricName))