This patch was heavily inspired by the existing 7z customizations that read the download token into the "postSigningData" file. In both cases, the installation self-extractor copies some data into the same temporary directory where the installer is written. It will then be up to the NSIS installer to copy that file into the installation directory (that work will be done later in this stack).

This patch also includes changes to some files that were regenerated based on the code changes made.
 - `mozilla_customizations.diff` was updated so that it still reflects all Mozilla-made code changes to 7z.
 - The `7zSD.ARM64.sfx` and `7zSD.Win32.sfx` executables were re-built from the new code.
 - `SFXSetup.vcxproj` was updated to use newer toolchains.

Differential Revision: https://phabricator.services.mozilla.com/D171109