Add WASM CI Support

[vgvassilev]

The wasm support should be compatible to what's already done for the xeus-cpp project where I would like to eventually adopt CppInterOp.

[mcbarton]

@vgvassilev I'm just waiting for the Windows CppInterOp build to pass in #181 and be merged, and then I plan add on a Windows cppyy build to the CI. I'll try to address this WASM support in that PR.

[vgvassilev]

Ok, awesome!

[vgvassilev]

Looks like the windows work is almost done. Maybe a good time to start the WASM work.