Provide more context for failed aggregation operators. (deephaven#5119)

engine/table/src/main/java/io/deephaven/engine/table/impl/by/AggregationOperatorException.java

@@ -0,0 +1,20 @@
+package io.deephaven.engine.table.impl.by;
+
+import io.deephaven.UncheckedDeephavenException;
+
+/**
+ * This exception provides more context when an aggregation operator throws an Exception.
+ *
+ * <p>
+ * When an aggregation operator results in an Error, this exception is added as a suppressed exception.
+ * </p>
+ */
+public class AggregationOperatorException extends UncheckedDeephavenException {
+    public AggregationOperatorException(String reason, Throwable cause) {
+        super(reason, cause);
+    }
+
+    public AggregationOperatorException(String reason) {
+        super(reason);
+    }
+}