[FIX] website_links: prevent display of huge list

- Create 80k UTM sources
- Go to the Website
- Promote a page (e.g. an event)
- Select a source

The web browser freezes.

It happens because Select2 tries to display all sources at once.

To prevent this, we force at least 3 characters before searching and
hence displaying the results. Note that a such high number of UTM
sources is reached because of automatic generation of random values in
mass mailing. Therefore, the combination of 3 characters narrows down
the search result drastically.

opw-2289249

closes odoo/odoo#54947

X-original-commit: 7c7986361704d7b82b115499e64c47eb74ab655f
Signed-off-by: Nicolas Martinelli (nim) <nim@odoo.com>

addons/website_links/static/src/js/website_links.js

@@ -58,6 +58,7 @@ var SelectBox = publicWidget.Widget.extend({
             createSearchChoicePosition: 'bottom',
             multiple: false,
             data: self.objects,
+            minimumInputLength: self.objects.length > 100 ? 3 : 0,
         });
     },