Swap the parameter order of `List.insert()` from `(item, index)` to `(index, item)`,
matching the convention used by most standard libraries. Update the C implementation
in `wren_core.c`, all documentation examples, and every test file to reflect the new
signature. Also restructure MSVC project files to match the new `src/cli/` and
`src/vm/` directory layout, add Visual Studio cache files to `.gitignore`, and fix
a trailing whitespace issue in `class_supertype`.