Move option-dependent configuration close to option

VecGeom options that require additional configuration, such as finding
external packages, typically place this config at a random place away
from the option.

Move option dependent configuration as close as possible to the option
triggering it, allowing for interdependencies.
6 jobs for bmorgan/simple-options in 10 minutes and 45 seconds (queued for 4 seconds)
latest
Status Name Job ID Coverage
  Build
passed clang-format #17218585

00:01:29

passed code_checks #17218586

00:10:45

passed with_NAVINDEX #17218588
cvmfs

00:03:48

passed with_ROOT #17218587
cvmfs

00:04:10

 
  External
passed jenkins

passed jenkins

00:59:59