BusinessTemplate: Import Big File's data property as Pdata

When i upgrade/install erp5_notebook in an instance which use neo storage instead
of zeo, Neo stopped immediately, as consequence, erp5_notebook can't be installed/upgraded.

The reason is in erp5_notebook, there has a one big file scipy.data.bin 157MB [1] which can't be
installed as it is  in neo. The solution suggested by @jm is to wrapper it by Pdata when install
a BT5.

See merge request !953

[1] https://lab.nexedi.com/nexedi/erp5-bin/blob/7d3505fd/bt5/erp5_notebook/SkinTemplateItem/portal_skins/erp5_notebook/scipy.data.bin