[web] Integrate icu4x_bidi into our build

[mdebbar]

The https://github.com/mdebbar/icu4x_bidi repo builds the icu4x_bidi JS and WASM files. We need to integrate it into our build in one of two ways:

1. Use gn (some examples here: https://github.com/unicode-org/icu4x/tree/main/ffi/gn).
2. Build manually and upload artifacts to CIPD.

[mdebbar]

The Skia CL has landed.

[github-actions[bot]]

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