Follow-up to #16208.
- Refactors build.rs behaviour to use `-exported_symbols_list` /
`--export-dynamic-symbol-list`
- Since all build systems now rely on a symbols list file, I have added
`generate_exported_symbols_list`, which derives the symbol list file
depending on the platform, which makes `tools/napi/generate_link_win.js`
redundant.
- Fixes a missed instance of `i8` being used instead of `c_char`
Co-authored-by: Divy Srivastava <dj.srivastava23@gmail.com>