Add confirmation dialog when making External Link to non-BNDB

[fuzyll]

What is the feature you'd like to have?
Users can make external links within a project directly to e.g. a .dll. This is probably not what they want to do and we should make sure it is with a confirmation dialog.

I'm thinking something like:

"You are making an external link to a raw file, rather than an analysis database (.bndb). Are you sure this is what you want to do?"

Checkbox: "Do not show this warning again for this analysis database" -> save into BNDB/QSettings

Buttons: Yes, No (save state of checkbox always, proceed or cancel depending on which button was pressed)

Is your feature request related to a problem?
Customers are annoyed when they double-click an external link to follow it and then have to suffer re-analysis on a big shared library. This shouldn't be what happens in most cases because they should link against a BNDB instead, but we allow them to link to the raw file, which may be what a user wants in specific cases, but not the general case.

Are any alternative solutions acceptable?
Anything that avoids having long analysis times when following an external link is potentially fine.

Additional Information:
Please add any other context or screenshots that would help us understand your feature request here.