Add the `adapt` command to produce components from core wasm

[elliottt]

This PR adds a component adapter based on the wasi_snapshot_preview1 adapter that also adapts the fastly host call abi. While the adapter can't yet be applied when running the serve command, it is possible to use the new adapt command to take wasm produced with a fastly compute SDK, and produce a component that can be run with Viceroy.