Admin types and authorizations

I am moving here a debate that we opened in github (a while ago!) and that we have not yet closed, although several valuable contributions have been made. Here I link the relevant issues for further discussion with the whole community: https://github.com/decidim/decidim/issues/2023 (here @xabier provided an schema of possible permissions and roles) https://github.com/decidim/decidim/issues/2056 (includes this gist from @mrcasals about module permissions and actions: https://gist.github.com/mrcasals/94503cebfd34b690ca10ab614557d5e8