Add "Remove properties with default values" option

[grochocki]

Adds an option to remove default properties (e.g., Grid.Row="0", Margin="0, 0, 0, 0", etc.). By default, this feature should address the most common cases, but should also be configurable to add more.

[grochocki]

We took another look at this one, and while it is certainly useful/interesting, it will be fairly complex to implement. This would also definitely need to be an option that is disabled by default. That being said, we do believe it is worth investigating further, as it could be a good candidate feature to move beyond styling into refactoring.