[native] set up CXX bridge

Summary:
create the ffi module that will be used to generate the bridge between C++ and Rust code

Depends on D4815

Test Plan: cargo build

Reviewers: tomek, karol

Reviewed By: tomek, karol

Subscribers: jon, ashoat, adrian, atul, abosh

Differential Revision: https://phab.comm.dev/D4820