Add vcpkg support for VS, delete unneeded files

[svew]

vcpkg

• Added vcpkg support for VS. All you should need now is to install vcpkg on your compute, configure the project, and the project will automatically download, install, and link packages
• Deleted src/imgui/, as it was a library that could be pulled from vcpkg
• Updated header references to match vcpkg folder structure

Miscellaneous

• Aggressively cleaned up the Barony.vcxproj file to make it more readable. Project configurations were extremely hard to diff before.
  • Assembly references, especially for fmod, may not work the same
  • Removed the after build scripts that copied binaries in unpredictable ways
• Added MSBuild target that will automatically copy over resource files from your game installation. You need to set the BARONY_GAME_DIR environment variable for it to work.
• Replaced rapidjson "GetObject()" calls with "GetObj()", because "GetObject()" is also a windows macro that was breaking the build

Todo

• Verify sure that fmod references work correctly
• Verify that all build configurations build and are accurate

Future Work

• Configure editor.vcxproj similarly
• Make CMake use vcxproj as well