Added TaskGroup property support to BackgroundTaskBuilder API

[godlytalias]

TaskGroup property support has been added to the BackgroundTaskBuilder API.

[godlytalias]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[AjitSurana]

@godlytalias, please elaborate the purpose of the TaskGroup property.

[godlytalias]

@godlytalias, please elaborate the purpose of the TaskGroup property.

Its used for grouping the background tasks. So that apps can get all the tasks under that particular group using AllTasks API (https://learn.microsoft.com/en-us/uwp/api/windows.applicationmodel.background.backgroundtaskregistrationgroup.alltasks?view=winrt-26100)

[AjitSurana]

@godlytalias, One follow up question - is it possible the same background task registration group has both Windows and Microsoft namespace background tasks? If so, AllTasks sort of properties return correct value?

[godlytalias]

@godlytalias, One follow up question - is it possible the same background task registration group has both Windows and Microsoft namespace background tasks? If so, AllTasks sort of properties return correct value?

It returns tasks registered by both namespace APIs as internally WinAppSDK API is calling platform SDK API only. Id, Name etc.. of the tasks will be the same