RDAP: Implement entity name search

Adds the ability to search for entities (contacts and registrars) by name.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=130305930

javatests/google/registry/model/contact/ContactResourceTest.java

@@ -129,7 +129,8 @@ public class ContactResourceTest extends EntityTestCase {
     verifyIndexing(
         contactResource,
         "deletionTime",
-        "currentSponsorClientId");
+        "currentSponsorClientId",
+        "searchName");
   }
 
   @Test