🐛 [Penpot] Opacity tokens do not work

Currently the opacity token does not work regardless of whether the value is in the format 0.5 or 50%.

Steps to recreate:

• Create a new opacity token and give it a value of 0.5 or 50%

• The value of the token shows 0

• Create a shape on the canvas with a fill

• Apply the opacity token on the shape

• The fill disappears

• Unapply the token and change the fill from the right panel

• The fill does not change and it is not possible to apply a fill again on the shape

Expected result:

• In the above example, if the opacity token is applied the opacity of the fill should reduce to 50%

• On unapplying the token and changing the fill from the right panel, the fill should change on the shape