Add Custom Field visible at Invoice Item level

[antonio]

We need to add an editable comment at Invoice Detail (or Invoice Item or Charge) level that has to  be visible in the Invoice Template.

At the moment:

- if we add a custom field at Charge level --> it is not visible in the invoice template

- if we add a custom field at INvoice Detail level --> it is not visible in the front end UI

Thank you

[iulianita]

it would be great if this was an out of the box field, something like "add a note" that would appear on a right click on each invoice item field, and that would after show on the invoice. 

thank you Antonio for the idea!