shim over lua differences

[zig-for]

Shim over differences between lua 5.1 and 5.4.

See https://github.com/TASEmulators/BizHawk/issues/3616 for source issues

• Allows connector script to select proper luasocket version between 5.1 and 5.4, depending on lua environment version
  • There's weirdness in Bizhawk 2.9 that requires absolute paths to modules, unfortunately
• Unifies folder structure between OSes and between dev and release versions - now always Connector.lua at the top level, with folders for each arch as siblings. In each arch folder, shared libraries of the form socket-{OS}-{LUA_MAJOR}-{LUA_MINOR}.{EXT} live.
  • This allows consistent testing between dev/release, as well as one less step to screw up when selecting the proper lua version

Tested on:

• [x] Win64 Bizhawk 2.8
• [x] Win64 Bizhawk 2.9
• [x] Linux Bizhawk
• [x] Snes9x