Support resolving components referenced by chart items from experiment

Previously all RVI -> Variable resolution was performed through the
configuration context which naturally doesn't work for entities that
only exist in an experiment context.

The editor still performs the default action on the first parent
variable's resource representation that has one.

gitlab #1250

(cherry picked from commit 61450d35)

Co-authored-by: Tuukka Lehtonen <tuukka.lehtonen@semantum.fi>