Remove ChangeAccess.byKey and byKeyRange

All callers of byKeyRange passed key.max() as the right endpoint, so
this can be safely replaced with a prefix query against the secondary
index. The number of callers notwithstanding, this was pretty
straightforward, although it does lead to the almost-recursive state
of calling InternalChangeQuery from ChangeQueryBuilder when expanding
the conflicts predicate.

Change-Id: I073d6ab179d3d5a5d8f0157aa3594fd3ea2cc81c

gerrit-server/src/test/java/com/google/gerrit/server/index/FakeQueryBuilder.java

@@ -26,8 +26,8 @@ public class FakeQueryBuilder extends ChangeQueryBuilder {
         new FakeQueryBuilder.Definition<>(
           FakeQueryBuilder.class),
         new ChangeQueryBuilder.Arguments(null, null, null, null, null, null,
-          null, null, null, null, null, null, null, null, null, null, indexes,
-          null, null, null, null));
+          null, null, null, null, null, null, null, null, null, null, null,
+          indexes, null, null, null, null));
   }
 
   @Operator