feat: associate MC photons in PhotoMultiplierHitDigi output

[c-dilks]

Briefly, what does this PR introduce?

Use edm4eic::MCRecoTrackerHitAssociation along with edm4eic::RawTrackerHit, to include the MC photon information in the output of PhotoMultiplierHitDigi

What kind of change does this PR introduce?

• Bug fix (issue #__)
• New feature (issue #__)
• Documentation update
• Other: __

Please check if this PR fulfills the following:

• Tests for the changes have been added
• Documentation has been added / updated
• Changes have been communicated to collaborators

Does this PR introduce breaking changes? What changes might users need to make to their code?

In general no breaking changes, but:

• until a new version of EDM4eic is released, which includes datatype MCRecoTrackerHitAssociation, this will not build in eic-shell
• may introduce conflicts with Noise injection in DRICH simulation #555, but likely straightforward to resolve

Does this PR change default behavior?

only for the dRICH (the only user of PhotoMultiplierHitDigi)

[c-dilks]

Ready when new version of EDM4eic is released; until then CI build will not succeed.

[c-dilks]

Next commits will use the new MultiFactory

[c-dilks]

Next commits will use the new MultiFactory

Working on #612 to keep this cleaner. Doesn't work yet...

[c-dilks]

Looks like all conversations are resolved. Let's wait til EDM4eic 2.0.0 makes it to the CVMFS image so the CI checks run.

[wdconinc]

Let's wait til EDM4eic 2.0.0 makes it to the CVMFS image

It builds... but poor scaling on a new build mechanism is causing the eic_container to eats its own tail in the scheduled nightly jobs... Working on that.

[wdconinc]

cvmfs sync fixed; restarted check.

[c-dilks]

CI passed, updating w.r.t. main

[c-dilks]

And confirmed these files are all identical to the ones on my irt-algo dev branch, where I do the real testing with the dRICH.

[wdconinc]

Just minor comments.