Add Tristate method to TextDecoration.State

[KingOfSquares]

Felt like a naturally missing piece

[BomBardyGamer]

Wouldn't it also be useful to add a asTriState conversion method, so you can convert a state to its tri state representation?

[kezz]

Wouldn't it also be useful to add a asTriState conversion method, so you can convert a state to its tri state representation?

I don't think so. This comes back to the reason they aren't the same in the first place. A TriState will never have its values change but a TextDecoration.State might.