Add auto height property for Grid widget

[samends]

Enhancement
Update the Grid widget so that if no height parameter is provided, the Grid's height would be set to the highest it can be, given a specific viewport. A new resource grid widget is in the works but this update can be backported to help those using earlier versions.

Package Version: 7.0.5

[tomdye]

I believe that once the Grid re-write is complete via the List implementation then this will work