feat: rewrite to C++ with JSI

[dcangulo]

Closes #38

I didn't test this much but it works. This is my first time trying JSI, so I think this needs more testing and review.

It's about 48% faster if I did the benchmark correctly using console.time.

References:

• https://blog.notesnook.com/getting-started-react-native-jsi/
• https://github.com/ammarahm-ed/react-native-jsi-template
• https://github.com/dcangulo/react-native-pkce-challenge/pull/122/files
• https://github.com/dsprenkels/randombytes
• https://android.googlesource.com/platform/bionic/+/master/libc/include/sys/random.h

[hannojg]

Hm, may I propose to use codegen to generate the CPP bindings? That feels more future proof

[efstathiosntonas]

Hey folks, is there any update on this? Thanks