Replace Asterius with GHC WASM

[avdv]

Is your feature request related to a problem? Please describe.
Asterius is deprecated and no longer worked on, in favor of the official GHC WebAssembly backend.

See announcement blog post, official documentation and https://gitlab.haskell.org/ghc/ghc-wasm-meta

Describe the solution you'd like
Replace the Asterius support and example using the ghc wasm backend.

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Related #205