Add Extensions to Enable/Disable tracking on a DbContext

If you want to force the dbContext to make a new db call instead of relying on its identity map, you can do so with this approach:

```
dbContext.ChangeTracker.QueryTrackingBehavior = QueryTrackingBehavior.NoTracking;
var fromDb = await dbContext. [whatever query]
dbContext.ChangeTracker.QueryTrackingBehavior = QueryTrackingBehavior.TrackAll;
```

Create extension methods that simply turn off tracking and then turn it back on that require less code than assigning to the QueryTrackingBehavior does.

Start by locating the existing extension methods and the DbContext tracking API used by this project. Add extensions that disable and restore tracking, then verify they provide the requested shorter equivalent to changing QueryTrackingBehavior around a query.

Written by the indexing model from the issue text.