[IMP] website: review frontend mini UI "Edit" button

The mini UI on the frontend as a connected backend user was a bit
confusing: the "Edit" button used the exact same design and wording as
the "Edit" button in the backend but it had not the same effect as it
did not enter edit mode but just redirected the user to the website
preview (client action iframe).

We still want the same behavior, we just needed another button design:

- Change the label from "Edit" to "Editor".

- Change the "pencil" fa icon with the website app icon (same as app
  switcher in enterprise).

- Use a dark color instead of the primary color. This reuses a dark
  color of the website edit mode.

closes odoo/odoo#100355

Signed-off-by: Romain Derie (rde) <rde@odoo.com>

addons/website/static/src/scss/website.ui.scss

@@ -45,7 +45,7 @@ $-mini-nav-size: 40px;
         overflow: auto;
     }
 
-    @each $-name, $-color in ('edit': $o-enterprise-primary-color, 'apps': $o-enterprise-color) {
+    @each $-name, $-color in ('apps': $o-enterprise-color, 'edit': $o-we-bg-lighter) {
         .o_frontend_to_backend_#{$-name}_btn {
             background-color: $-color;
 
@@ -55,6 +55,12 @@ $-mini-nav-size: 40px;
         }
     }
 
+    .o_frontend_to_backend_edit_btn > img {
+        height: 1.8em;
+        margin-right: 0.5em;
+        border-radius: 0.25rem;
+    }
+
     &:hover {
         &:before, .o_frontend_to_backend_icon {
             transform: scale(.3);

addons/website/views/website_templates.xml

@@ -192,7 +192,7 @@
                        t-attf-href="/web#menu_id=#{menu['id']}&action=#{menu['action'] and menu['action'].split(',')[1] or ''}"/>
                 </div>
                 <a groups="website.group_website_restricted_editor" href="#" title="Edit this content" class="o_frontend_to_backend_edit_btn px-3 d-flex align-items-center justify-content-center text-decoration-none">
-                    <i class="fa fa-pencil me-1"/>Edit
+                    <img src="/website/static/description/icon.png"/>Editor
                 </a>
             </div>
         </div>