Add ffi and JS wasm package

[SHAcollision]

No description provided.

[SHAcollision]

@tipogi @amirRamirfatahi IMO this works and we can merge. Yet there is many caveats:

• We have not yet settled for ffi or oop for the wasm. All ffi functions exist, but only PubkyAppUser uses OOP. Ideally we use OOP as interface in JS as well, however the final decision should be taken as we incorporate this library into the client's /contexts/_pubky.tsx . The API of the wasm is probably far from ideal, it might not be fully functional.
• Web tests are not comprehensive (I don't think we need them to be as long as unit tests are comprehensive).
• The NPM package readme is TODO , it is not ready for release, but the readme should be written before releasing.

Overall there is still quite some work left to do, but until we can get to implement this WASM into our client, it's hard to settle for some decisions.