cw20-ics20 incorrectly encodes `ack_success`.

[0xekez]

The ICS 20 spec imagines the ACK success type to be JSON encoding of "binary 0x01 base64 encoded". They then suggest this to be the string "AQ==".

The ics20 implementation seems to do the JSON encoding of the ASCII character '1' (ASCII codepoint 49) wrapped in an enum.

cw-plus/contracts/cw20-ics20/src/ibc.rs

Lines 67 to 70 in d0b68db

	fn ack_success() -> Binary {
	let res = Ics20Ack::Result(b"1".into());
	to_binary(&res).unwrap()
	}

The result is that ack_success yields [123, 34, 114, 101, 115, 117, 108, 116, 34, 58, 34, 77, 81, 61, 61, 34, 125], whereas (I think) it ought to yield [34, 65, 81, 61, 61, 34]. The expected output is an array of bytes corresponding to ASCII character codes of AQ== surrounded by quotation marks (ASCII codepoint 34).

[0xekez]

Looks like this is well tested. Figure this is more likely me misreading the spec, or some difference in the practical implementation.

cw-plus/contracts/cw20-ics20/src/ibc.rs

Lines 399 to 409 in a24bed3

	#[test]
	fn check_ack_json() {
	let success = Ics20Ack::Result(b"1".into());
	let fail = Ics20Ack::Error("bad coin".into());
	let success_json = String::from_utf8(to_vec(&success).unwrap()).unwrap();
	assert_eq!(r#"{"result":"MQ=="}"#, success_json.as_str());
	let fail_json = String::from_utf8(to_vec(&fail).unwrap()).unwrap();
	assert_eq!(r#"{"error":"bad coin"}"#, fail_json.as_str());
	}