Stop requesting column statistics for preview columns

Will be reverted as part of deephaven#188

Fixes deephaven#4825

web/client-api/src/main/java/io/deephaven/web/client/api/JsTable.java

@@ -1435,6 +1435,10 @@ public Promise<JsPartitionedTable> partitionBy(Object keys, @JsOptional Boolean
      */
     @JsMethod
     public Promise<JsColumnStatistics> getColumnStatistics(Column column) {
+        if (column.getDescription() != null && column.getDescription().startsWith("Preview of type")) {
+            // TODO (deephaven-core#188) Remove this workaround when we don't preview columns until just before subscription
+            return Promise.reject("Can't produce column stats for preview column");
+        }
         List<Runnable> toRelease = new ArrayList<>();
         return workerConnection.newState((c, state, metadata) -> {
             ColumnStatisticsRequest req = new ColumnStatisticsRequest();