Remove unused files

frontend/src/metabase/lib/query/named.js

-/* @flow */
-
-export function stripNamedClause(mbql) {
-  if (mbql && mbql[0] === "named") {
-    return mbql[1];
-  } else {
-    return mbql;
-  }
-}

frontend/src/metabase/qb/components/gui/AggregationPopover.jsx

-/* @flow */
-
-import React from "react";
-
-import AggPopover from "metabase/query_builder/components/AggregationPopover";
-
-import type { Aggregation, ExpressionName } from "metabase/meta/types/Query";
-import type { TableMetadata } from "metabase/meta/types/Metadata";
-
-type Props = {
-  aggregation?: Aggregation,
-  tableMetadata: TableMetadata,
-  customFields: { [key: ExpressionName]: any },
-  onCommitAggregation: (aggregation: Aggregation) => void,
-  onClose?: () => void,
-  availableAggregations: [Aggregation],
-  showOnlyProvidedAggregations: boolean,
-};
-
-const AggregationPopover = (props: Props) => (
-  <AggPopover {...props} aggregation={props.aggregation || []} />
-);
-
-export default AggregationPopover;

frontend/src/metabase/qb/components/gui/BreakoutPopover.jsx

-/* @flow */
-
-import React from "react";
-
-import FieldList from "metabase/query_builder/components/FieldList.jsx";
-
-import type { Breakout } from "metabase/meta/types/Query";
-import type { TableMetadata, FieldOptions } from "metabase/meta/types/Metadata";
-
-type Props = {
-  maxHeight?: number,
-  breakout?: Breakout,
-  tableMetadata: TableMetadata,
-  fieldOptions: FieldOptions,
-  onCommitBreakout: (breakout: Breakout) => void,
-  onClose?: () => void,
-};
-
-const BreakoutPopover = ({
-  breakout,
-  tableMetadata,
-  fieldOptions,
-  onCommitBreakout,
-  onClose,
-  maxHeight,
-}: Props) => (
-  <FieldList
-    className="text-green"
-    maxHeight={maxHeight}
-    tableMetadata={tableMetadata}
-    field={breakout}
-    fieldOptions={fieldOptions}
-    onFieldChange={field => {
-      onCommitBreakout(field);
-      if (onClose) {
-        onClose();
-      }
-    }}
-    enableSubDimensions
-    alwaysExpanded
-  />
-);
-
-export default BreakoutPopover;