hoist onStart into correct interface

adapters-api/src/main/java/io/nosqlbench/engine/api/activityimpl/OpDispenser.java

@@ -82,5 +82,4 @@ public interface OpDispenser<T> extends LongFunction<T>, OpResultTracker {
 
     T apply(long value);
 
-    void onStart(long cycleValue);
 }

adapters-api/src/main/java/io/nosqlbench/engine/api/activityimpl/OpResultTracker.java

@@ -17,6 +17,7 @@
 package io.nosqlbench.engine.api.activityimpl;
 
 public interface OpResultTracker {
+    void onStart(long cycleValue);
     void onSuccess(long cycleValue, long nanoTime, long resultsize);
     void onError(long cycleValue, long resultNanos, Throwable t);
 }