Address modules in ConditionalTask that are not consumed by any module in the Path

[makortel]

Continuation of #365
See cms-sw/cmssw#37305 (comment)

[makortel]

See first how the HLT ends up using Alpaka modules (i.e. module type resolver) to understand how necessary ConditionalTask will be (or can it be removed?).

[makortel]

I learned this week that the HLT wants to continue using ConditionalTask for both Run3 menu and Phase2 developments as to make the menu management easier. Dealing with modules in ConditionalTask that are not consumed by any module in the Path is considered important.

[makortel]

I have a first attempt here (with which I hit a wall, commit messages tell the story)
cms-sw/cmssw@master...makortel:cmssw:conditionalTaskNonConsumed

In further discussion with HLT they decided prefer explicitly scheduled menu (after they can get there after moving from CUDA+SwitchProducer to Alpaka+ModuleTypeResolver), so for time being this feature is not needed. They asked though, for phase 2 development purposes, for an ability to print out the modules that are in ConditionalTask but not consumed by any module in any associated Path. I think I can deliver that rather quickly based on what I did already. I'll open a new issue for that. This issue goes back to "Ready".