Support for cosmos json address

[ethanfrey]

User Story

First off, very nice progress and I do like the interfaces you provide. But I want to create amino json that I can sign properly.

Why Is this Needed?

One point I noticed looking over the readme, is that addresses are an array of bytes in the json output. However, to create proper "canonical json" for signing I belive them must be in the bech32 format of cosmosacct1q..... The base64 binary inside of signatures is easy enough to read, properly encoded in binary, and is not included in signbytes, so this shouldn't be an issue

{"type":"auth/StdTx","value":{"msg":[{"type":"cosmos-sdk/MsgMultiSend","value":{"inputs":[{"address":[59,58,243,13,132,163,164,202,233,7,236,93,136,166,181,175,236,69,48,186],"coins":[{"denom":"cyb","amount":"10000"}]}],"outputs":[{"address":[94,222,114,42,196,107,51,203,139,142,219,243,137,60,54,250,139,153,46,168],"coins":[{"denom":"cyb","amount":"10000"}]}]}}],"fee":{"amount":[{"denom":"cyb","amount":"0"}],"gas":"200000"},"signatures":[{"pub_key":{"type":"tendermint/PubKeySecp256k1","value":"AhsYAP9gkxVAHYTAbNs7hs7JfuA/oBjsqnykXyu0Bvb6"},"signature":"pUxtPTWBvpM04CJq69DgJL4ZzCTigWFtI4LZ5JBqCoYOt1/82+sWXCU1A1lvrQyekkdScezxqnnZFOwXgyNQHQ=="}],"memo":"elonmusk"}}

Definition of Done

Json output is compatible with the json used for sign bytes in cosmos hub tx signing

Additional Information