Pulp modularity

[FrostyX]

modularity - check if it works (separate directory for results), ask forman folks (and others) whether this is needed at all, module-hotfixes

[FrostyX]

We got module hotfixes for free with #3383

Building modules probably doesn't work. I think it could be doable but personally, I would vote for not implementing this, keeping all projects with modules in the backend storage. Maybe as one of the latest tasks.

If modularity was implemented through CoprDirs, this would be much easier task. But modularity predates that feature and uses its custom implementation. Relevant issue #1576

[FrostyX]

We researched the future of Copr Modularity in #3476 and a decision to deprecate and eventually drop all Copr Modularity code has been made. The reasoning and the retirement schedule can be found in my blog post https://frostyx.cz/posts/copr-modularity-the-end-of-an-era

So I am closing this ticket as WONTFIX. Copr projects with modules will be kept in the current storage until we get to the point when we remove all Modularity data from our database and our storage, and then they will be moved to Pulp.