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/main/java/com/google/gerrit/server/ChangeUtil.java

@@ -526,12 +526,7 @@ public class ChangeUtil {
 
     // Try isolated changeId
     if (!id.contains("~")) {
-      Change.Key key = new Change.Key(id);
-      if (key.get().length() == 41) {
-        return db.get().changes().byKey(key).toList();
-      } else {
-        return db.get().changes().byKeyRange(key, key.max()).toList();
-      }
+      return asChanges(queryProvider.get().byKeyPrefix(id));
     }
 
     // Try change triplet