[Invoices] : add a "share" button

I would like to have the ability to share invoices with other email addresses, without having to add a user.

Current way to share invoices:
- Create a user
- Go in the notifications sections of this user
- enable "new invoices"

Desired way to share invoices:
-Go to the invoices section
-Have a "share" button

Why?
The customer does not wish to create a user in order to share invoices with some email adresse.

Video explaining the feature request: https://www.loom.com/share/ddafcd9c560d49f79248a1d080594bff

zendesk ticket:

https://doitintl.zendesk.com/agent/tickets/55624