New room list: move sort menu in room list header (#29983)

* feat: move sort and preview into room list header vm

* feat: move sort menu into room list header

* test: update tests

* test:update snapshots

* chore: remove secondary filter tests

* test(e2e): update screenshots

res/css/views/rooms/RoomListPanel/_RoomListSecondaryFilters.pcss

@@ -10,16 +10,3 @@
     margin: var(--cpd-space-2x);
     margin-left: var(--cpd-space-1x);
 }
-
-.mx_RoomListSecondaryFilters_roomOptionsButton {
-    /* Size the button appropriately (should this be in em, maybe,
-     * so it gets bigger with font size? These values taken from the figma.
-     */
-    width: 28px;
-    height: 28px;
-    margin-left: auto;
-
-    svg {
-        color: var(--cpd-color-icon-primary);
-    }
-}