add compensation for entities to be converted to scalar values for BC

refs https://github.com/zikula-modules/News/issues/135

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| Refs tickets  | https://github.com/zikula-modules/News/issues/135
| License       | MIT
| Doc PR        | -

ping @rgasch