Add diff logic and send daily Spec11 emails with new threats

For each registrar, the daily email will only include threats that did not appear
in the prior run's email.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=228889972

java/google/registry/config/RegistryConfigSettings.java

@@ -92,7 +92,8 @@ public class RegistryConfigSettings {
     public String whoisDisclaimer;
     public String rdapTos;
     public String rdapTosStaticUrl;
-    public String spec11EmailBodyTemplate;
+    public String registryName;
+    public List<String> spec11WebResources;
     public boolean requireSslCertificates;
   }