Fix wrong default data structure in 'getReportTableData' (https://github.com/woocommerce/woocommerce-admin/pull/1042)

* Fix wrong default data structure in 'getReportTableData'

* Update tests

* Change default prop for tableData from null to an empty object in ReportTable

plugins/woocommerce-admin/client/analytics/components/report-table/index.js

@@ -118,7 +118,7 @@ ReportTable.propTypes = {
 };
 
 ReportTable.defaultProps = {
-	tableData: null,
+	tableData: {},
 	tableQuery: {},
 };
 

plugins/woocommerce-admin/client/store/reports/test/utils.js

@@ -451,7 +451,9 @@ describe( 'getReportTableData()', () => {
 	const response = {
 		isError: false,
 		isRequesting: false,
-		items: [],
+		items: {
+			data: [],
+		},
 	};
 
 	const query = {

plugins/woocommerce-admin/client/store/reports/utils.js

@@ -305,7 +305,9 @@ export function getReportTableData( endpoint, urlQuery, select, query = {} ) {
 		query: tableQuery,
 		isRequesting: false,
 		isError: false,
-		items: [],
+		items: {
+			data: [],
+		},
 	};
 
 	const items = getReportItems( endpoint, tableQuery );