New functionalities of Storage.Pickers: SettingsIdentifier; FileTypeIndex; Title; PickMultipleFoldersAsync; ShowOverwritePrompt; CreateNewFileIfNotExists#6052

DinahK-2SO wants to merge 6 commits intomainmicrosoft/WindowsAppSDK:mainfrom

user/DinahK-2SO/feature_settingsidentifier_filetypefilterindexmicrosoft/WindowsAppSDK:user/DinahK-2SO/feature_settingsidentifier_filetypefilterindexCopy head branch name to clipboard