Cleanup some old patches and rename the unicode one.
Add a new patch adapted from https://phabricator.services.mozilla.com/D130410, which fixes the `local` incorrect subfolder in the virtualenv environment. This should fix issues on Fedora.
On Debian, there is a remaining issue with `site-packages` becoming `dist-packages` on Debian Testing (and probably Unstable). This is fixable with a hack which I will do in a separate patch after getting input from Debian maintainers.
**Note to myself** I should set all patches eol as native when I commit this.
Refs #6676