Rebase Client WASM

This is the underlying WASM that powers the JavaScript Rebase Client. This is published seperately, in addition to the JavaScript Rebase Client, to allow for other Rust-based WASM projects to import it directly. This allows downstream applications to only compile / ingest 1 source of WASM, rather than multiple blobs which may contain redundant dependencies.

This README will be updated with more details soon.