feat: add data-wasm-opt-params

[maratik123]

This fixes #900

[ctron]

Thanks for the change. It looks good. I'd prefer to have the value stored as Vec<String> though. And do the parsing when retrieving this from the attribute.

[maratik123]

@ctron Done, but the code become more cumbersome

[ctron]

I'd kept the original let mut args: Vec<&str> = vec![&arg_output, &arg_opt_level, &target_wasm]; … but it works the same way.