Move restore from backend to tools

Move the "restoreCommitLogs" command from the backend module to the tools
module so it's easier to access with nomulus.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=156768389

java/google/registry/env/common/backend/WEB-INF/web.xml

@@ -181,12 +181,6 @@
     <url-pattern>/_dr/task/exportCommitLogDiff</url-pattern>
   </servlet-mapping>
 
-  <!-- Restores commit logs. -->
-  <servlet-mapping>
-    <servlet-name>backend-servlet</servlet-name>
-    <url-pattern>/_dr/task/restoreCommitLogs</url-pattern>
-  </servlet-mapping>
-
   <!-- Deletes commit logs. -->
   <servlet-mapping>
     <servlet-name>backend-servlet</servlet-name>