Turn CheckApiAction into a standard-ish epp endpoint

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=125335634

java/google/registry/flows/soy/DomainCheckFeeEpp.soy

@@ -0,0 +1,26 @@
+{namespace registry.soy.api autoescape="strict"}
+
+/** Domain check fee request for one domain. */
+{template .domaincheckfee}
+{@param domainName: string}
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<epp xmlns="urn:ietf:params:xml:ns:epp-1.0">
+  <command>
+    <check>
+      <domain:check xmlns:domain="urn:ietf:params:xml:ns:domain-1.0">
+        <domain:name>{$domainName}</domain:name>
+      </domain:check>
+    </check>
+    <extension>
+      <fee:check xmlns:fee="urn:ietf:params:xml:ns:fee-0.6">
+        <fee:domain>
+          <fee:name>{$domainName}</fee:name>
+          <fee:command>create</fee:command>
+          <fee:period unit="y">1</fee:period>
+        </fee:domain>
+      </fee:check>
+    </extension>
+    <clTRID>CheckApiAction</clTRID>
+  </command>
+</epp>
+{/template}