[Bug]: Returning `Err(Vec<u8>)` From a Contract Function Should be Passed to Calling Contract

[0xNeshi]

What happened?

Currently when the error data is empty, the error message is converted to:

let selector = decode_selector(calldata);
format!("function not found for selector '{selector}' and no fallback defined").as_bytes().to_vec()

This doesn't align with actual blockchain behavior, which passes empty error data as-is.

platform

• linux
• windows
• macos

Expected behavior

Motsu should just pass the error data as-is, i.e. the if e.is_empty() check should be removed.

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