TD-2872 Added frequency word on Course reports screen of Tracking system

Author: manishagarwalnhs

DigitalLearningSolutions.Web/Views/TrackingSystem/Centre/Reports/EditFilters.cshtml

@@ -55,7 +55,7 @@
                            end-date-checkbox-hint-text="Check this box to specify an end date. If left unchecked will display data until today." />
 
       <vc:select-list asp-for="@nameof(Model.ReportInterval)"
-                      label="Report by"
+                      label="Report by frequency"
                       value="@reportIntervalValue.ToString()"
                       hint-text=""
                       required="true"