Ports/boost: Fix download link, fix paths in patches

[Kusekushi]

Boostorg's artifactory instance is down, let's switch to github instead.

[timschumi]

Do you know by chance why the tarballs differ? It seems like they even have different paths inside, and not just a changed hash due to differences in the way it was archived.

[Kusekushi]

They cherry pick files during packaging on releases, see https://github.com/boostorg/release-tools/blob/develop/ci_boost_release.py
Now, at the time of that specific release this script was programmed to upload the cherry picked tarball to both github and their jfrog instance, but it apparently didn't work..? No idea honestly why it didn't work out in this case. I'll continue to try to understand their release process tho if needed so I can give a proper response to that.

[Kusekushi]

Might also be that they just didn't put in a github token when running their first script, but at the time ran https://github.com/boostorg/release-tools/blob/develop/github_releases.py instead. Would explain the discrepancy.