Add applied patch information such that it would be visible in the Phabricator review

[fuzzy-coats]

Human review accuracy and speed could be improved if information about the patches applied in the patch step could be embedded automatically (perhaps in the commit message) such that it is visible in the Phabricator review. This information would also be very useful for code archeology purposes.

Right now my review process for a manual vendoring is to:

1. check the patch stack for changes to the related moz.yaml
2. read patches section of the moz.yaml, either from Searchfox, Mercurial, or from Phabricator
3. determine if there were any patch changes in this patch set
4. look at the correct version of those patches, either in Searchfox, Mercurial, or from Phabricator
5. check that each hunk was applied appropriately

While not unreasonable on its face, this process involves a lot of context switches.