Add XjcToDomainResourceConverter for RDE import

With some code cleanup/refactoring/formatting by Ben McIlwain.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=141199855

java/google/registry/model/reporting/HistoryEntry.java

@@ -62,6 +62,8 @@ public class HistoryEntry extends ImmutableObject implements Buildable {
     HOST_DELETE_FAILURE,
     HOST_PENDING_DELETE,
     HOST_UPDATE,
+    /** Resource was created by an escrow file import. */
+    RDE_IMPORT,
     /**
      * A synthetic history entry created by a tool or back-end migration script outside of the scope
      * of usual EPP flows. These are sometimes needed to serve as parents for billing events or poll