[FIX] web: do not show cursor pointer on m2m badge without color

before this commit: when many2mnay_tags widget does not have color_field in
options still hovering over many2many_tags badge shows cursor pointer, while
it should display default cursor and if there is color field given in options
then cursor should be pointer.

after this commit: cursor pointer will be displayed only when color field is
given in options else shod cursor default.

task-2451204

addons/web/static/src/scss/fields.scss

@@ -133,11 +133,14 @@
             flex: 0 0 auto;
             border: 0;
             font-size: 12px;
-            cursor: pointer;
             user-select: none;
             display: flex;
             max-width: 100%;
 
+            &.dropdown {
+                cursor: pointer;
+            }
+
             a {
                 color: inherit;
             }