### What?
Prevents the preventLeave dialog from showing if a clicked link is about
to open in a new tab.
### Why?
Currently, no external link can be clicked on the edit page if it was
modified, even if the link would not navigate the user away from that
page but open in a new tab instead.
### How?
We don't trigger the preventLeave dialog if
- the target of a clicked anchor is `_blank`
- the user pressed the command or ctrl key while clicking on a link
(which opens link in a new tab)
398607fdc7