tests: avoid unnecessarily looking inside .hg/ in test-narrow* Many of the narrow tests were looking at .hg/narrowspec. I think most of them were written before we added `hg tracked`, but now that we have that command, we should fix the tests. There were also a few instances of tests looking at .hg/dirstate. I fixed those to use `hg files` instead. Differential Revision: https://phab.mercurial-scm.org/D4093