[Comm-opaque2] Add wasm build to client

Summary:
Build wasm and js bindings for the client sided opaque
code.

https://linear.app/comm/issue/ENG-3265

Depends on D7022

Test Plan:

nix develop
cd shared/comm-opaque2
wasm-pack build

# pkg directory contains js, ts, and wasm artifacts
ls pkg/

Reviewers: varun, ashoat, tomek, bartek, O1 Nix

Reviewed By: varun, ashoat, O1 Nix

Subscribers: atul

Differential Revision: https://phab.comm.dev/D7087