Don't count wasm4 commands as WASI commands

[Michael-F-Bryan]

It looks like we blindly assume all commands are WASI when inspecting a *.webc file.

You can reproduce this using the f0rodo/[email protected] package.

$ wasmer --version --verbose
wasmer 3.0.0 (3a105 2022-11-20)
binary: wasmer-cli
commit-hash: 3a105194470a955ba663509fc8dae60d3085717c
commit-date: 2022-11-20
host: x86_64-unknown-linux-gnu
compiler: singlepass,cranelift,llvm

$ wget https://registry-cdn.wapm.io/packages/f0rodo/rusty/rusty-1.0.0.webc

$ wasmer run wasmer/[email protected] --dir . -- show ./rusty-1.0.0.webc
Error: Unable to load the package

Caused by:
    no "atom" or "wasi.atom" or "emscripten.atom" found in command Command {
        runner: "https://webc.org/runner/wasm4/command@unstable_",
        annotations: {
            "wasm4": Map(
                {
                    Text(
                        "atom",
                    ): Text(
                        "rusty",
                    ),
                    Text(
                        "package",
                    ): Null,
                    Text(
                        "main_args",
                    ): Null,
                },
            ),
        },
    }

Ideally, the webc crate's get_atom_name_for_command() function would use the manifest to figure out the atom's ABI automatically, but in the meantime we should skip wasm4 commands when generating bindings.

[Michael-F-Bryan]

@ayys originally mentioned this on November 21st on Slack.