tests: show that adding an already included path still calls narrow_widen() This patch adds tests demonstrating that we still go to the server in non-ellipses widening when we have that path already on the client and there is nothing new to download. The next patch will try to make client side logic smart and not go to the server if we don't need to download anything. Differential Revision: https://phab.mercurial-scm.org/D5182