Add a checkbox in the export user interface to select wether you want exporting all files too or not.

Problem/Motivation

On my site I have a few fotobooks with some 250 fotos. If I try to export my site it takes 45 minutes to make a jar file of 150 MBytes. This way, it has a few disadvantages:
1. Importing a file of 150 MByte creates a PHP error because I should augment some PHP values to be able read in the file (post_max_value??)
2. It takes ages to export all files. I can't test if the import take as long too.

My fotos doesn't change frequently. Therefor they should not be transferred to the other site. Most of the time only entities change.

Therfore, it should be be handy if there is a knob on the export form that disables the jar-ing of the files and only includes the entities.
I know it can be done with Drush but I can't use Drush.

Steps to reproduce

Export a site with some fotos.

Proposed resolution

Remaining tasks

User interface changes

Checkbox on export form

API changes

In the ContentExportForm.php file, in the submitForm function on line 100:
$serializer_context['include_files'] = 'none'; in stead of 'folder'

Data model changes