Move Safetyhook mess into a mirror repo

[Headline]

This patch reimplements all of the modifications made to safetyhook to make it compatible with SourceMod, but does so in the actual source/inc files so we can possibly take upstream changes in the future and make the amalgamation scripts a part of our build process.

I didn't attempt to call the amalgamation scripts in our builds yet - they're hard-pathed still (see alliedmodders/safetyhook@0c3a4c0), but this gets us most of the way there.

Someone should test that this stuff still works before we take it in

EDIT: I haven't compiled this for linux, either, so builds may fail with safetyhook errors

[Headline]

Assuming those linux builders pass we can take this in if it tests ok with the TODO of:

1. Generate the amalgam stuff with ambuild
2. build this into a lib and link instead of including this in everything

[GAMMACASE]

Providing some input on testing this fork, works great rn for me on x64 platforms on windows and linux.

[rowedahelicon]

Tested this on Debian 12, server boots up fine and a detour I use for testing worked out without problems.