Webforms Entity Print settings are ignored using VBO

Problem/Motivation

When using the "Download PDF" action in the results view of a webform, a pdf is given, without application of the header, footer,... etc defined under the settings of the webform.

Steps to reproduce

1. create a form, and define a header under Settings > General > Third party settings > Entity print.
2. create a submission
3. go to the results page of the form, select a submission, and select the "Download PDF" operation/action, and click the "Apply to selected items" button. The PDF does NOT have the header that is defined.
4. click on the same submission to go to its HTML or Table view, and click "Download PDF". This PDF does have the header as defined in the settings.

Proposed resolution

Apply the header, footer,... as defined in the webform's settings also when downloading the PDF from the result overview page, or more general when using the VBO action.

Remaining tasks

?

User interface changes

none

API changes

?

Data model changes

?