items-by-period (#2)

Reviewed-on: #2
Co-authored-by: Vishesh 'ironeagle' Bangotra <aetoskia@gmail.com>
Co-committed-by: Vishesh 'ironeagle' Bangotra <aetoskia@gmail.com>

src/components/Dashboard/Dashboard.models.ts

@@ -1,6 +1,7 @@
 import * as React from "react";
 import {
-  ReportData
+  ReportData,
+  GroupKey,
 } from "../../features/report";
 
 export type DashboardMode = "expense" | "income";
@@ -11,6 +12,7 @@ export interface DashboardState {
   mode: DashboardMode;
   periodType: DashboardPeriodType;
   selectedPeriodId: DashboardSelectedPeriodId;
+  selectedGroupKey: GroupKey | null;
   comparison: boolean;
 }