Provide optional survey for users to evaluate their values and improve dataset

[mitar]

We could ask users to do a survey similar to 8values which would stay completely private and used only anonymously as part of the research dataset. That could then improve usefulness of the dataset because there would be some additional information linked with every anonymous user.

We could also ask for some other census information.

Maybe we could show those options in settings only if the user agrees on contributing data for research purposes.

We will have to obtain a new/updated IRB for that though.