Determine wasm binary filename based on CPU architecture

[larry0x]

In mars-integration-test, we load the wasm binary file the following way:

let path = format!("../{artifacts_dir}/{snaked_name}.wasm");

However, on ARM computers, the filename generated is instead contract_name-aarch64.wasm, which causes the test to fail.

I suggest we do something like this (untested, not sure if will work):

let path = {
    #[cfg(target_arch = "aarch64")]
    format!("../{artifacts_dir}/{snaked_name}-aarch64.wasm")
    #[cfg(not(target_arch = "aarch64"))]
    format!("../{artifacts_dir}/{snaked_name}.wasm")
};

[larry0x]

The same case in the tests for mars-swapper-osmosis

[larry0x]

This can be done using the cfg-if crate:

use cfg_if::cfg_if;
use std::{env, path::PathBuf};

let manifest_dir = PathBuf::from(env::var("CARGO_MANIFEST_DIR")?);
let wasm_file_path = manifest_dir.join({
    cfg_if! {
        if #[cfg(target_arch = "aarch64")] {
            "../../artifacts/cw_bank-aarch64.wasm"
        } else {
            "../../artifacts/cw_bank.wasm"
        }
    }
});