Add proxy for TableViewRow.
Implement native row objects.

Refactored data model to get a variant object from
the native row provided during setData().
Eventually this code will also convert dictionary objects
into row proxies.
Implement dictionary row support.

Any dict objects are now converted to rows during setData().
Implement row updates.

Updating a row's property will now update the model
and cause the visual node for that row to be updated.
Implement TableViewRow.leftImage
Fix assets location.

This was breaking URL properties for images and other resources.
Fix table view row click events.

Provide the correct row proxy and index by
keeping a pointer back to the row in the data item.
Reset list item image when setting empty URL.

This fixes an issue with empty space appearing
where the left image would go when no image is provided.
Fix segfault when bad data pointer is set.
Clean up list item data when native object is destroyed.
Merge branch 'TIMOB-8839'

Adds support for table view row proxies.
Only "simple" rows are supported at this time.