fix(batch): add OPENED state for when the stream hasn't been started

Author: bevzzz

src/main/java/io/weaviate/client6/v1/api/collections/batch/BatchContext.java

@@ -173,7 +173,7 @@ void setClosing(Exception ex) {
 
     this.queue = new ArrayBlockingQueue<>(DEFAULT_QUEUE_SIZE);
     this.batch = new Batch(DEFAULT_BATCH_SIZE, maxSizeBytes);
-    setState(CLOSED);
+    setState(OPENED);
 
   }
 
@@ -835,6 +835,13 @@ List<Runnable> shutdownNow() {
     }
   }
 
+  final State OPENED = new BaseState("OPENED") {
+    @Override
+    public void onEnter(State prev) {
+      closed = false;
+    }
+  };
+
   final State CLOSED = new BaseState("CLOSED") {
     @Override
     public void onEnter(State prev) {