Create Holdings interface that includes parent holdings (ETF)

libs/common/src/lib/interfaces/holding-with-parents.interface.ts

@@ -0,0 +1,5 @@
+import { Holding } from './holding.interface';
+
+export interface HoldingWithParents extends Holding {
+  parents?: Holding[];
+}

libs/common/src/lib/interfaces/index.ts

@@ -19,6 +19,7 @@ import type { Export } from './export.interface';
 import type { FilterGroup } from './filter-group.interface';
 import type { Filter } from './filter.interface';
 import type { HistoricalDataItem } from './historical-data-item.interface';
+import type { HoldingWithParents } from './holding-with-parents.interface';
 import type { Holding } from './holding.interface';
 import type { InfoItem } from './info-item.interface';
 import type { InvestmentItem } from './investment-item.interface';
@@ -79,6 +80,7 @@ export {
   Filter,
   FilterGroup,
   HistoricalDataItem,
+  HoldingWithParents,
   Holding,
   ImportResponse,
   InfoItem,