Experiment - WebAssembly Golang + Bazel

Experimenting with some issues encountering with WebAssembly, Golang & Bazel

Notes

• Confirmed issue with syscall/js in the basecase with using goos and goarch (toolchains passed as orgs better option?)
• Using a genrule sufficient to workaround the case
• Base case with a simple calculator, using just base HTML
• js.Value conversions, framework wrapper to exist to handle the interop?
• Directory layout of cmd/ and app feels a bit off, but does help keep the bits separate