Switch from association to link

[tmadlener]

BEGINRELEASENOTES

• Switch from Association to Link in the conversion from EDM4hep to LCIO to accomodate for the new naming from (EDM4hep#341)
• Add test to make sure that conversion of Links from EDM4hep to LCIO works as expected

ENDRELEASENOTES

Fixes #199 (I think). @andresailer was this what you were referring to in that issue?
Fixes key4hep/k4EDM4hep2LcioConv#93

[jmcarcell]

This is what #199 is referring to since now it's impossible to find "Association" in the type name.

[tmadlener]

Seems, I didn't merge this yet. AFAIU this solves the issue and can be merged, right?

[jmcarcell]

Maybe there should be a test doing something with links? Otherwise this can just not be caught if there is another problem like this one.

[tmadlener]

There is already a test with links global_converter_maps that goes from LCIO to EDM4hep (which works without problems apparently). I added a new test that also checks the other direction. I added this as a completely separate test that uses one new Transformer for creating the Links in EDM4hep and then it uses another new Marlin Processor for checking it's contents. Prior to the fixes this test fails, so it does indeed check that links are converted.

[tmadlener]

@jmcarcell do you want to have another closer look? Otherwise, I would merge this later today.

[jmcarcell]

So we don't have !=?

[tmadlener]

We do, especially because for LCIO this is just comparing pointers. (We would also have it for EDM4hep). This is a remnant from copy-pasting.