Refactor: Move getReadableID out of filesloaderutils

Overview The helper function getReadableID(obj *objectsenvelopes.ScanObject) in core/pkg/resourcehandler/filesloaderutils.go is a generic helper that is buried in the resourcehandler package.

Solution Move this function to a shared utility package (core/cautils/scanobjectutils.go) and update its callers to use cautils.GetReadableID.