Paragraph entity fields are not getting saved

Here is a shot at it.
The problem is causing by the fact that the function entityShouldBeSaved is only checking base fields of the entity, thus when a reference is present it will only check its target_id which won't change if any of the referenced entity field is changed.

The patch add a nested logic to drill into fields of entity_reference (nodes, terms, medias...) and entity_reference_revisions (used for paragraphs).

We had to add a check for $new_field to be a valid field as in some case we had strings., so I guess a few eyeballs on this should help.

Fix in #5 saved my day,
Thank you