[FIX] mail: fix placeholder scrollbar with long name

Currently, Chrome show a scrollbar when the placeholder is multilined.
Overflow hidden will avoid the scrollbar and we place a nowrap on the
placeholder text to avoid the multiline.

task-2416058

closes odoo/odoo#65213

X-original-commit: dfbbb18f39f5e546bb8bea34e395bdf1c1b49dab
Signed-off-by: Sébastien Theys (seb) <seb@odoo.com>
Signed-off-by: Alexandre Kühn (aku) <aku@odoo.com>

addons/mail/static/src/components/composer_text_input/composer_text_input.scss

@@ -22,6 +22,12 @@
     border: none;
     overflow: auto;
 
+    &::placeholder {
+        white-space: nowrap;
+        overflow-x: hidden;
+        text-overflow: ellipsis;
+    }
+
     &.o-composer-is-compact {
         // When composer is compact, textarea should not be rounded on the right as
         // buttons are glued to it