[cache] fix a cache issue with an entity created without relation cache prefill Prefilling the relation cache has its benefits sometimes, but for massive imports it may be a memory hog. The caches should be kept coherent even if there was no prefill. Closes #3828155.

addressbook
basket
blog
book
calendar
comment
company
email
file
folder
i18ncontent
keyword
link
mailinglist
person
tag
timeseries
vcsfile