fix: Aggregations should be available when creating a rollup (#1129)

- When there is a rollup config, aggregations go through the rollup
config
- https://github.com/deephaven/web-client-ui/blob/a069543812b6c544957ebf664e0918e98a3affbf/packages/iris-grid/src/IrisGrid.tsx#L1288
- Allow aggregations to be accessed when using a rollup config

Author: mofojed

packages/iris-grid/src/IrisGrid.tsx

@@ -4195,7 +4195,7 @@ export class IrisGrid extends Component<IrisGridProps, IrisGridState> {
       model.isCustomColumnsAvailable,
       model.isFormatColumnsAvailable,
       model.isRollupAvailable,
-      model.isTotalsAvailable,
+      model.isTotalsAvailable || isRollup,
       model.isSelectDistinctAvailable,
       model.isExportAvailable,
       this.toggleFilterBarAction,