feat: make getCells synchronous

[AyushAgrawal-A2]

related to #1447, #1409, #1114

This pr is meant to explore usage of Atomics and SharedArrayBuffer, for communication between workers. Using this we can block(sleep) a worker thread and execute synchronously, instead of using async / await

Pros:

• c, cell, cells, getCells, rel_cell and rc works now synchronously without using async / await. This clear ambiguity of when to add async / await, for enclosing functions (#1114).

Cons:

• Overhead due to encoding and decoding from shared memory.
• To use SharedArrayBuffer, we need to meet the Security requirements.
  • For local dev - Chrome treats localhost / 127.0.0.1 as secure context. COOP, COEP headers are added in vite.config.js. So everything works without switching to https.
  • For deployment - It will require all deployment to be secure and for quadratic-client we need to add headers mentioned in Security requirements.

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[davidfig]

This works great. Outside of the necessary server changes, is there anything else that makes this a POC and not ready for review? We'll also need this ported to JS so we can remove the await requirement there as well.

[AyushAgrawal-A2]

@davidfig ready for review

[davidfig]

Awesome. Works wonderfully.