This updates `fmt` to the latest version and moves to just being a copy
of their repo to make updating easier (no editing their cmake / figuring
out which files to minimally include).
The motivation for this is now that we switched to C++ 20, there were a
ton of deprecated function usages that is going away in future compiler
versions. This gets rid of all those warnings.
This sets out the bones of a Jak 3 build, many things are stubbed out,
guessed, or copied from Jak 2 but it should at least be good enough to:
run `task set-game-jak3`
launch the repl
run builds from the repl
build outputs themselves are untested but the build itself runs without
errors
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Co-authored-by: Tyler Wilding <xtvaser@gmail.com>