[Tokens] Value in "Spectrum" theme missing in "Express" theme

[Westbrook]

--spectrum-picker-border-width is available here, but not in the Express version of this file.

If the value is shared between both themes, then shouldn't it exist in this file so that it can be discovered in both context?

Currently, when an application is delivered without both themes on the same page, the Express Picker delivers as follows: Due to the fact that the math in: https://github.com/adobe/spectrum-css/blob/dec16329ab9e241df6188223485791f986a2dea3/components/picker/index.css#L411 Cannot be completed.

[pfulton]

Tracking this in Jira here: https://jira.corp.adobe.com/browse/CSS-595