Rename WhoisServer and WhoisHttpServer to actions

These servlets are converted to actions during daggerization. Calling them servers are misleading.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=190942237

java/google/registry/whois/WhoisMetrics.java

@@ -31,7 +31,7 @@ import org.joda.time.DateTime;
 /**
  * Instrumentation for WHOIS requests.
  *
- * @see WhoisServer
+ * @see WhoisAction
  */
 public class WhoisMetrics {