NewVersionBehaviorTracker.checkVersions() should allow cell type to be DELETE

`MajorCompactionScanQueryMatcher.match()` states that  "7. Delete marker need to be version counted together with puts they affect" which corresponds to a code path that can happen when KEEP_DELETED_CELLS is true. However, `NewVersionBehaviorTracker.checkVersions()` asserts that type cannot be DELETE.

The AssertionError can be verified by running `TestKeepDeletes.testBasicScenario` with "-Dhbase.tests.new.version.behavior=true" after fixing it up to work as expected with NEW_VERSIONS_BEHAVIOR:
--- a/hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestKeepDeletes.java
+++ b/hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestKeepDeletes.java
@@ -135,7 +135,7 @@ public class TestKeepDeletes {
     g.setMaxVersions();
     g.setTimeRange(0L, ts+2);
     Result r = region.get(g);
-    checkResult(r, c0, c0, T2, T1);
+    checkResult(r, c0, c0, T2);

     // flush
     region.flush(true);

Some more info in the following comment: https://issues.apache.org/jira/browse/HBASE-21545?focusedCommentId=16719510&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-16719510