Add fallback to wasm_bindgen. NFC

[stephenduong1004]

This PR adds a fallback to wasm_bindgen when looking for wasm-bindgen in $PATH

[sbc100]

I'd actually rather keep this local/isolated if possible rather than adding WASM_BINDGEN to shared.py, given there is only one user.

Is there some reason you cannot put wasm-bindgen in the $PATH?

[sbc100]

I had hoped to avoid making this a configurable setting.. but maybe that isn't possible?

[stephenduong1004]

Not really, I can certainly update my $PATH; I just thought this is the preferred way. Updated the PR to remove the configuration and additionally search for wasm_bindgen

[sbc100]

I would prefer maybe just depend on PATH in this case, rather than add another configuration point to maintain and test.

[stephenduong1004]

Done!

[sbc100]

Ah, is it sometimes called by different names? Maybe mention in the PR description why it could have two different names.

[guybedford]

I'm not aware of a toolchain that builds wasm_bindgen personally, it would be good to know what this applies to further.