Remove CC0 waiver from TreeBASE studies

[kcranston]

Once opentree issue #670 is fixed, we need to purge the CC0 waivers from TreeBASE studies where we mistakenly applied it by default.

[kcranston]

Issue referenced above fixed, so should update studies. Worth also updating legacy treebase DOIs for better duplicate checking (see opentree issue 907).