Add NavButton interaction color animation states

[jarolrod]

Introduces the missing NavButton interaction color animation states as detailed in #231, except there are issues with the sizing of the components themselves.

Dark Mode

Default	Hovered	Pressed

Dark Mode

Default	Hovered	Pressed

As can be told from the screenshots the sizing of the component itself isn't correct; this needs to be addressed, potentially in a follow-up.

The first commit allows for us to use the NavButton correctly with these new background states but also fixes an issue where the Right Caret buttons in the NodeSettings page were much bigger than in the other areas we use this button. A follow-up can contain this button in a nice component.

[johnny9]

ACK 20edc75

Buttons behave as expected and no QML errors appear. I think this is an improvement over the flat buttons with no state.

As can be told from the screenshots the sizing of the component itself isn't correct; this needs to be addressed, potentially in a follow-up.

Fixing the size of these buttons will help with the focus state as well. I tried adjusting for it but it wasn't a great solution so I agree its best to just approach it as another issue/PR.