UX: position of group user table dropdown, border (#20593)

app/assets/javascripts/discourse/app/templates/group-index.hbs

@@ -208,7 +208,6 @@
                     @canAdminGroup={{this.model.can_admin_group}}
                     @canEditGroup={{this.model.can_edit_group}}
                     @onChange={{action "actOnGroup" m}}
-                    @options={{hash placementStrategy="absolute"}}
                   />
                   {{! group parameter is used by plugins }}
                 </div>

app/assets/stylesheets/common/base/directory.scss

@@ -127,6 +127,7 @@
 
   &__column-header,
   &__cell,
+  &__cell--empty,
   &__cell--user-field {
     display: flex;
     border-bottom: 1px solid var(--primary-low);

app/assets/stylesheets/common/components/group-member-dropdown.scss

@@ -1,3 +1,12 @@
 .group-member-dropdown {
   text-align: left;
+
+  .select-kit-body {
+    // this is a little hacky
+    // but solves an issue with a wrapping container query on .directory-table-container
+    // which breaks our popper positioning in this one specific instance
+    inset: unset !important;
+    transform: unset !important;
+    right: 0 !important;
+  }
 }