Fix for HER-1985 H3: SurtPrefixDecideRule forgets learned/seed-derived/seed-directive SURT prefixes in checkpoint-resume

* SurtPrefixedDecideRule.java
    make class implement Checkpointable, save surt prefixes to json on checkpoint and load them on recover
* profile-crawler-beans.cxml
    make main SurtPrefixedDecideRule a top-level bean so that it can be checkpointed
* Checkpoint.java, CheckpointService.java
    add some FINE level logging during checkpointing and recovery

engine/src/main/java/org/archive/crawler/framework/CheckpointService.java

@@ -40,6 +40,7 @@ import org.archive.spring.ConfigPath;
 import org.archive.spring.ConfigPathConfigurer;
 import org.archive.spring.HasValidator;
 import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.BeanFactoryUtils;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextAware;
@@ -222,6 +223,9 @@ public class CheckpointService implements Lifecycle, ApplicationContextAware, Ha
         }
         
         Map<String,Checkpointable> toCheckpoint = appCtx.getBeansOfType(Checkpointable.class);
+        if (LOGGER.isLoggable(Level.FINE)) {
+            LOGGER.fine("checkpointing beans " + toCheckpoint);
+        }
         
         checkpointInProgress = new Checkpoint();
         try {