build(scripts): Split out build:wasm step
build(scripts): Split out build:wasm step

So we can pass arguments to build.js with `npm run build:wasm --`.

thewtex/ITKBridgeJavaScript,InsightSoftwareConsortium/ITKBridgeJavaScript,thewtex/ITKBridgeJavaScript,thewtex/ITKBridgeJavaScript,InsightSoftwareConsortium/ITKBridgeJavaScript,InsightSoftwareConsortium/ITKBridgeJavaScript