* With Microsoft having finally relinquished the terms of use of DBX binaries (where their
previous legalese pretty much made it illegal for anyone who wasn't an OS manufacturer to
download DBX for use in applications) we can now formally embed, as well as download the
DBXs when they are updated.
* This is accomplished by querying the https://github.com/microsoft/secureboot_objects
GitHub repo (which is now the official repository for the UEFI Forum's revocation files)
through api.github.com and checking the timestamps of the last commit on the relevant files.
If a more recent DBX is found than the one embedded (or a previously downloaded one), Rufus
will now prompt the user to download it, as part of its regular update check (if enabled).
* Note that, since there have been no official revocations for them yet, IA64, RISCV64 and
LoongArch64 are currently placeholders.
* Also note that we currently don't use this mechanism for Microsoft's SVN revocations, as
we already have a more efficient check for it through SBAT.
* Also fix the handling of the RISCV64 MD5Sum UEFI bootloader, whose offset was incorrect.
