Create a small generic Netpromoter score UI that talks to the IAppFlow event system

[cs-util]

Using the IAppFlow interface a fully generic and reusable net promoter score UI can be created that shows after a specified time and collects reports the users feedback

• This should use the LocalAnalytics system to build on top of the UsageRule , and this way allow to let the developer specify when the UI should be shown and how often. See the Ui15_NewsManager example how the NewAppUsedXDaysRule is used for example
• To explain the individual components like LocalAnalytics, UsageRule and the UsageRuleFactory separatly and at the same time fully understand them, it would be good to add additional XUnit tests next to the existing ones, that focus on collecting analytics events and then asking the UsageRule system if a certain condition is met like "The user used the app at least 10 days and there wasnt any net promoter score notification fired in the last 5 days (see NewNotificationMinXDaysOldRule)"