Add a way to differentiate people with same name and surname combination in donation forms

[hundrex]

Context

As some people can have both same name and surname, it is possible to encounter some of those case in the application. It poses no problem on the member list, as they have different contact information.
But this becomes a problem in donation forms, where we choose these people on a simple list with no other details than their name and surname. We need a way to differentiate these people in these forms

Todo

• add a way to differentiate people with same name and surname combination in new donation form
• add a way to differentiate people with same name and surname combination in edit donation form

[hundrex]

It might also be a good idea to check all the other forms for this use case.