[FIX] mass_mailing: show media modal when fullcreen

Whenever the user clicked on the fullscreen in mass_maliing, then
trying to show the media modal was not possible as the div that
contains it was hidden.

Task-2731907

closes odoo/odoo#85314

X-original-commit: 4026bc2075b7109dd18471aabf11ff3f76d6c57d
Signed-off-by: David Monjoie (dmo) <dmo@odoo.com>

addons/web_editor/static/src/scss/web_editor.backend.scss

@@ -59,7 +59,7 @@
         z-index: 1001 !important;
         border: 0;
     }
-    > :not(.modal):not(.modal-backdrop) {
+    .tooltip-field-info {
         display: none;
     }
     .o_form_fullscreen_ancestor {