[FIX] web: fix dialog overlap on fullscreen

Steps to reproduce
==================
1. Open marketing automation and select any campaign.
2. Click 'edit' on activity or click 'add new activity'.
3. Select existing mail template and open it to edit the template.
4. Select template on mail body page and click fullscreen from snippet.
The activity modal dialog appear at top of everything.

Technical
=========
In prior version, the 'owl_dialog.js' file includes a 'display' function that
applies the 'o_inactive_modal' class to the inactive dialog, adjusting its
z-index. However in master, the commit https://github.com/odoo/odoo/commit/036307ba260ef1a08e80a14f7cffe1ef9a24021c removes the'owl_dialog.js'
file, resulting in the class no longer being applied.

After this commit
=================
The 'o_inactive_modal' class is applied based on the state 'data' to
position the dialog below the fullscreen editor.

Task-3512850

closes odoo/odoo#139165

Signed-off-by: Jérémy Hennecart (jeh) <jeh@odoo.com>

addons/web/static/src/core/dialog/dialog.xml

@@ -5,7 +5,7 @@
         <div class="o_dialog" t-att-id="id" t-att-class="{ o_inactive_modal: !data.isActive }">
             <div role="dialog" class="modal d-block"
                 tabindex="-1"
-                t-att-class="{ o_technical_modal: props.technical, o_modal_full: isFullscreen }"
+                t-att-class="{ o_technical_modal: props.technical, o_modal_full: isFullscreen, o_inactive_modal: !data.isActive }"
                 t-ref="modalRef"
                 >
                 <div class="modal-dialog modal-dialog-centered" t-attf-class="modal-{{props.size}}">