ECWID-170718 New IS: New endpoint for aggregated statistics reports

- added new reportType siteGroupActivity

Author: JulBal

src/main/kotlin/com/ecwid/apiclient/v3/dto/report/enums/ReportType.kt

@@ -44,4 +44,5 @@ enum class ReportType {
 	siteActivity,
 	siteSocialActivity,
 	siteAggregatedActivity,
+	siteGroupActivity,
 }