Force include https-everywhere in incremental mar update

We should include an older version of https-everywhere in the upcoming release. This won't be a problem for new installations. However, any recently run instance of Tor Browser mostlikely automatically upgraded to the newest https-e version (2020.3.16), so we should include the older version (2019.11.7) in our incremental mar files.

2019.11.7 is the version we included in the last Tor Browser version, so it won't be included in the incrementals. It seems like we can force inclusion in make_incremental_update.sh.

I see two options:

1. (tor-browser) Patch tools/update-packaging/make_incremental_update.sh so it always include https-everywhere (and then we revert/drop that patch at the next rebase)
2. (tor-browser-build) Patch tools/update-responses/gen_incrementals so it passes -f $ext_path/$https_everywhere_dir/* $packed_https_e_path (with appropriate paths) when it calls make_incremental_update.sh?

If there are alternatives, we can consider those, too.