`SamplingResult` should be a Component

[nrfulton]

The SamplingResult class has a ton of constituent parts but is currently defined as a CBlock. This needs to be changed. Breaking this out from #249 because it should be done regardless of whether we merge that PR.

[nrfulton]

This requires changes to -contribs as well.

[nrfulton]

This is controversial. Moving out of Jan '26 sprint for now.