Allow a CSVDataset to define `fetch_probes`.

4 jobs for csv-fetch-probe in 11 minutes and 1 second (queued for 9 seconds)
Status Job ID Name Coverage
  Build
passed #233703
docker
build_linux_37

00:05:59

84.0%
passed #233704
docker
build_linux_38

00:05:59

84.0%
passed #233701
intel macos
build_macos_intel_37

00:11:01

84.0%
passed #233702
intel macos
build_macos_intel_38

00:11:00

84.0%