experiment: mechanism for interacting with external Wasm components

[rvanasa]

This PR introduces a standardized import which can be used for cross-language interoperability via the Wasm component model specification.

Progress:

• Import component.call in compiled Wasm module
• Add componentCall prim function
• Enable this feature with the -import-component flag (e.g. moc -wasi-system-api -import-component ...)
• Use new error code (M0200) when trying to use this feature without the -import-component flag
• Add unit test
• Replace Nat32 arg with Blob
• Replace Nat32 return type with Blob

Next steps

• Generalize wit:component:call to support arbitrary component imports?

Note that this only works in runtimes with support for the component model:

• Wasmtime works out of the box.
• Wasmi can be used in Rust canisters via wasm_component_layer.

An alternate approach would be to enable passing the names of arbitrary Wasm imports. While this seems like it would be beneficial at first glance, the component model architecture tends to favor a pattern of defining a standard interface (for example, the WASI CLI world) and then "plugging" exports into corresponding imports (see WAC for how this specifically works).

The current approach follows this pattern with the following WIT world:

package motoko:component;

world motoko {
    import component: interface {
        call: func(value: list<u8>) -> list<u8>;
    }
}

It's possible to plug a Rust component into this interface using something similar to the following WAC composition:

package motoko:composition;

let rust = new rust:component {};

let motoko = new motoko:component {
    component: rust,
    ...
};

export motoko.run;

[crusso]

@rvanasa I took a look and (hopefully) got CI working for you in #4584.

The problem was that moc -t doesn't even enter compile.ml, so you weren't generating the error when just running moc -t (as the tests in test/fail (which are mostly type checker test do).

Feel free to merge into your branch or ignore...

[github-actions]

Comparing from 75c59e1 to 80ebfef:
In terms of gas, 2 tests regressed and the mean change is +0.0%.
In terms of size, 5 tests regressed and the mean change is +0.1%.