[FIX] web: prevent unwanted click on enter keypress

Pressing ENTER on a button element triggers an additionnal 'click' event.
Since this 'unwanted' click caused some issues in a few cases, we prevent it.
Moreover, there isn't currently any known case in which this event is useful.

Before this commit:
No modification of the initial behaviour on ENTER key

After this commit:
ENTER key pressed in abstract fields has its default behaviour suppressed