Shop Packs - CSV Exports: export items within a group

[babsgosgens]

The recently added group feature could be used to export a subset of items. This will help in organised export of shop pack items, whereby only the items in the group can be selected when exporting as CSV.

This will help the user, but may also reduce the numbers of items requested from the database for download.

The way I see this work, is by adding a CSV Export to the dropdown list. In this example (see images below), the resulting list would only show the 3 items in this pack:

Combined with suggestion #1005 it would like: