Make Branch.NameKey enforce full ref names

Also remove some now redundant ref fixes before constructing
Branch.NameKeys.  This reduces the proliferation of "correcting" code.

Change-Id: I5d9864d7c6ea7252f05a4ccabcf124cb014c4fae

gerrit-server/src/main/java/com/google/gerrit/server/change/ConsistencyChecker.java

@@ -307,8 +307,7 @@ public class ConsistencyChecker {
       return;
     }
     if (dest == null) {
-      problem("Destination ref not found (may be new branch): "
-          + change.getDest().get());
+      problem("Destination ref not found (may be new branch): " + refName);
       return;
     }
     RevCommit tip = parseCommit(dest.getObjectId(),