[FIX] portal: fix dialog box border

Before this commit
===================
1). Go to website slides.
2). Open any Course.
3). Click on 'Add a review' or 'Edit your review'.
  -> We can see that textarea and div both have a border.

After this commit
=================
When we are in the pop-up view div border will be not shown.

Task-3623765

closes odoo/odoo#149434

Signed-off-by: Warnon Aurélien (awa) <awa@odoo.com>

addons/portal/static/src/scss/portal.scss

@@ -378,8 +378,13 @@ img, .media_iframe_video, .o_image {
         margin-bottom: 15px;
     }
 
-    .o_portal_chatter_composer_body textarea {
-        border: 0;
+    .o_portal_chatter_composer_body  {
+        textarea {
+            border: 0;
+        }
+        > div {
+            border: 1px solid var(--o-border-color);
+        }
     }
 
     .o_portal_chatter_messages {

addons/portal/static/src/xml/portal_chatter.xml

@@ -37,7 +37,7 @@
                     <div class="flex-grow-1">
                         <div class="o_portal_chatter_composer_input">
                             <div class="o_portal_chatter_composer_body d-flex flex-nowrap align-items-start flex-grow-1 mb-4">
-                                <div class="d-flex flex-column flex-grow-1 border rounded-3">
+                                <div class="d-flex flex-column flex-grow-1 rounded-3">
                                     <div class="position-relative flex-grow-1">
                                         <textarea rows="4" name="message" class="form-control rounded-3 shadow-none" placeholder="Write a message..." style="resize:none;"/>
                                     </div>