Bech32 address test doesn't satisfy the specification

[conr2d]

Summary of Bug

According to BIP-173, bech32 encoder should generate a string with lowercase letters only, and checksum validation should be processed with the lowercase form.

https://en.bitcoin.it/wiki/BIP_0173#Bech32

Uppercase/lowercase

The lowercase form is used when determining a character's value for checksum purposes.

Encoders MUST always output an all lowercase Bech32 string. If an uppercase version of the encoding result is desired, (e.g.- for presentation purposes, or QR code use), then an uppercasing procedure can be performed external to the encoding process.

Decoders MUST NOT accept strings where some characters are uppercase and some are lowercase (such strings are referred to as mixed case strings).

However, types/address_test.go generates mixed-case addresses, and contains invalid checksum based on the mixed-case string. This blocks merging the latest version of btcutil/bech32.

cosmos-sdk/types/address_test.go

Lines 377 to 382 in 22cd778

	{"empty address", args{"prefixA", []byte{}}, "", false},
	{"empty prefix", args{"", addr20byte}, "", true},
	{"10-byte address", args{"prefixA", addr10byte}, "prefixA1qqqsyqcyq5rqwzqfwvmuzx", false},
	{"10-byte address", args{"prefixB", addr10byte}, "prefixB1qqqsyqcyq5rqwzqf4xftmx", false},
	{"20-byte address", args{"prefixA", addr20byte}, "prefixA1qqqsyqcyq5rqwzqfpg9scrgwpugpzysn6j4npq", false},
	{"20-byte address", args{"prefixB", addr20byte}, "prefixB1qqqsyqcyq5rqwzqfpg9scrgwpugpzysn8e9wka", false},

Version

22cd778

Steps to Reproduce

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