As a Watchlist Expiry user, I want to watch both the new and original page (when moved) for the identical specified amount of time, so that the behavior can match that of permanently watched pages during a move.
**Background:** Right now, when a page is moved, all watchers automatically watch the new page and the original page. Now, with the addition of watchlist expiry, if a page is moved, we want the same functionality in place (except for temporary watches). Otherwise, a temporarily watched page will become a permanently watched page upon it being moved. This ticket is only for the back-end support of moving for temporary watches (which is MVP for release). The ticket to allow watching in the UI [TBD].
The same issue exists when moving pages via the API. When moving a page using the API and the new page is meant to be watched (e.g. `watchlist=watch`), but you //don't// provide an expiry, the new page is always watched indefinitely. It does not use the expiry of the old page, if one existed.
* Add support so, that when a page is moved, all temporary watchers continue to watch the new page and original page for the temporary watch period
* Do not change functionality or behavior for permanently watched users