Incoming handler virtualization

@dicej did some exploration here on what would be involved in https://github.com/dicej/WASI-Virt/commit/99d950f104d60899865dd133ad3a2b113b4672ca.

This currently hits limitations with wasm-compose due to a cyclical case, which would need to be acyclified via a wrapper adapter module with a table.

There are new WIT techniques being planned here which should resolve these issues though more generally. In addition cycle fixes for wasm-compose should also be able to unblock progress here.

In addition the approach above should be able to combine with component rewriting to form a proper wrapper virt for HTTP incoming requests.

Joel please correct me where I'm wrong and feel free to fill in some more background on this as well.

Start with the linked WASI-Virt commit and review the discussion around wasm-compose's cyclical case. Investigate the planned WIT techniques, wasm-compose cycle fixes, and component rewriting for HTTP incoming requests. Done means a general incoming-handler virtualization approach is defined and the current cycle limitation is unblocked.

Written by the indexing model from the issue text.