Fix export of Design Tokens

[mrm1st3r]

Due to Tokensbrücke not handling scopes in the way we need, the export of tokens is currently broken.

The fast workaround would be to remove scopes from figma.

The better, but not immediate, solution would be to fix the Tokensbrücke Plugin. (Either by reporting an issue or contributing a fix on our own)

[fabiangaukler]

It turns out that a new version of TokensBrücke fixing this issue was already released, but it still takes some days for Figma to review and approve it. As soon as it's released, we can safely use it. In the meantime I manually downloaded and ran the release locally to have a working set of tokens.

The only minor drawback is that the handling of opacity now is a bit broken. @MarioBiehs would it be ok for you if the 4 primitive values of the opacity variables also have "layer opacity" as scope? If yes that would be great because this will make the variables conversion to css work.

[fabiangaukler]

#102