inno: move inno installer files to contrib/packaging/inno
Let's isolate the inno installer files to their own directory
so the separation between things is clearer.
This required adjusting a few relative paths and references to
the old directory.
Differential Revision: https://phab.mercurial-scm.org/D6059
tests: make test-status.t compatible with test-check-module-imports.t
Otherwise the later fails on Python 3.
Differential Revision: https://phab.mercurial-scm.org/D6072