Enable the Win32 platform layer to hot-reload program DLLs at runtime

[rdw-software]

This is yet another experiment, aimed at removing the need to embed a full Lua VM only to speed up iteration cycles.

The feature is somewhat hacky and has a number of caveats, but in principle allows a realtime(ish)-editing workflow:

• Start watch.cmd to automatically rebuild continuously (Future: Use OS to monitor for file system changes instead)
• Start the Win32 runtime once and let it hot-reload the program DLL (Future: Enable snapshots/serialization/fallbacks)
• When program code is edited, the runtime will seamlessly reload and use the updated version from a different DLL
• A full restart is still required whenever the data layout changes, but tuning parameters should "just work" already
• The platform runtime can't detect changes to the platform layer itself... Not sure if that's possible, or even desirable

Also works inside the debugger, though file paths/PDB references may need to be remapped. That's trivial, if annoying.

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TODOs:

• Update CI/pre-release artifacts (build artifacts have changed)
• Pass controller/inputs to the program DLL (instead of updating the state directly)
• Disable this feature in release builds (presumably it's enough to just load the DLL at startup)
• Streamline the output paths to avoid having leftover garbage files when watch.cmd fails
• Fix profiling UI display; program updates and render times are no longer separate
• Fail gracefully instead of silently when the program DLL cannot be loaded (alert or placeholder "world" scene?)
• Maybe store additional metadata inside the executable (program name, memory requirement, platform features?)