Avoid multiple representations of the same data

[shankari]

This is a generalization of #31
Right now, the expectation in the codebase is that the config will contain the additional columns to be displayed.
But if the surveyinfo is MULTILABEL then (at least now), there are only a certain number of labels.
Requiring them to be specified in multiple places just increases the possibility of a misconfigured instance.

@AlirezaRa94 this is why I wanted the configs to be integrated and not to have a separate "admin dashboard" file.
Note also that the addition columns are not really a permission issue.

[shankari]

Enketo is trickier, but even if the surveyinfo is ENKETO, we already specify the important information to be pulled out and displayed in the label.