Replace the Legacy DataSvc and use the new Frame based one

[tmadlener]

BEGINRELEASENOTES

• Switch the converters to use the new Frame based DataSvc components introduced in key4hep/k4FWCore#100
• Use the MetaDataHandle for the CellIDEncoding string passing in the converters
• Update the test inputs and expected outputs in order to be able to work with these changes
• Update the documentation to also include the "workaround" for key4hep/k4FWCore#125

ENDRELEASENOTES

Needs

• Codify some of the implicitly assumed conventions AIDASoft/podio#439
• Introduce a quick workaround for collection metadata creation k4FWCore#119
• Make MetaDataHandle handle all keys correctly k4FWCore#124
• New input file for the clicRec_edm4hep_input test (needs to go to the cernbox from where it is downloaded)

Includes changes from

• Switch LCIO to EDM4hep conversion to use k4EDM4hep2LcioConv functionality #114
• Fix formatting and usage of Legacy components in tests #118

TODO

• Release Notes (waiting to see how this goes once all the bits and pieces are in place)
• Remove k4LCIOReader dependency
• Update tests (provide new input file)

[tmadlener]

I opened key4hep/k4FWCore#125 to keep track of the non-zero (4) exit code of k4run and switched to simply ignoring the return value in the edm4hep converter test for now. It shouldn't really matter since there are checks afterwards that will catch problems, just debugging the test will become a bit more cumbersome.

[jmcarcell]

I would prefer this to be opt-in: we give the command without || true and then an explanation on why you may want to use it if running in a test or something like that, but that's kind of expert knowledge that is unlikely to be useful for most people

[tmadlener]

The problem is that these bits of the documentation are run in the doctest workflow and without any handling of the non-zero exit code from k4run they will fail.

[jmcarcell]

Same comment as above, not needed for most people so it can be separated from the code that is going to be copied and pasted most of the time