Involved Persons of Distributions always empty

[semeyerz]

Describe the bug
The Involved Persons box of distributions is always empty.

Expected behavior
Either no box or a box that lists all involved persons aggregated from the projects?

[scymtym]

I just realized that this is slightly more complicated. At the moment, the box is not always empty. In the (relative rare) case that the distribution has a recipe.maintainer entry, the persons listed there are displayed (subject to GDPR, see https://citkat-citec.bob.ci.cit-ec.net/distribution/build-generator-nightly.xml for an example).

So this seems like another instance of the pattern in which things can be either directly (recipe.maintainer in the distribution recipe) or indirectly (a person related to one of the included project versions in any capacity) related. We should probably come up with a general way to indicate this.