Add space to the bottom of the room summary actions below leave room (#29270)

* Add space to the bottom of the room summary actions below leave room

* 8x not 6x

* Spacing needs to be within the scoll content, add it to the bottom of the leave action

* Update RoomSummaryCard-test.tsx.snap

* Fix snapshot and add screenshot test

src/components/views/right_panel/RoomSummaryCard.tsx

@@ -441,6 +441,7 @@ const RoomSummaryCard: React.FC<IProps> = ({
                 <Separator />
 
                 <MenuItem
+                    className="mx_RoomSummaryCard_leave"
                     Icon={LeaveIcon}
                     kind="critical"
                     label={_t("action|leave_room")}