feat/1012: Improve Tx API in SDK

[jurevans]

Resolves #1012

This PR refactors the response from the various build_ functions, including build_batch, to be able to provide via the SDK package a deserialized object that can be inspected and destructured. I think in the future, the @heliax/namada-sdk should never return a reference to a Rust struct, as it's clunky and breaks TS convention to use. This PR returns an normal TS type where values can be inspected and destructured.

• New Tx type and related schema with all values required in client
• Hook up Tx to existing build functions
• Update SDK package to deserialize these values from Rust before returning to client
• Regenerate docs once types & API are finalized: See new Tx type in https://github.com/anoma/namada-interface/blob/33c6485fc044f5212c5bb2501c306f8d5b6db170/packages/types/docs/classes/TxMsgValue.md

NOTES

Instead of returning an instance of a Rust struct BuiltTx to the client, return a deserialized tx value:

import { WrapperTxProps } from "@namada/types";

// We'll use borsh schemas instead of type defs, but essentially what the user
// will see is this:

type SigningData = {
  publicKeys: string[];
  threshold: number;
  feePayer: string;
  accountPublicKeysMap?: Uint8Array;
  owner?: string;
}

type Tx = {
  // tx hash
  hash: string;
  // tx bytes
  bytes: Uint8Array;
  // args used to create args::Tx in namada-sdk
  args: WrapperTxProps;
  // deserialized signing data 
  signingData: SigningData[];
}

This makes the result of any build function something that can be inspected or destructured.

Testing

• Simply build this branch and test existing Tx functionality

Example Tx

{
    "args": {
        "token": "tnam1q87wtaqqtlwkw927gaff34hgda36huk0kgry692a",
        "feeAmount": "0.000001",
        "gasLimit": "300000",
        "chainId": "internal-devnet-43.35fd77a4447",
        "publicKey": "tpknam1qr4w8d26738k7zmhxhsp9987puunenrjt4kxp5f5k8wlgey3zzuyqg9tgqh",
        "memo": ""
    },
    "hash": "0CEBA68C9BB9391B5481C46069B32EFE45758E77C5114D676455F471A711A2F5",
    "bytes": {
        "type": "Buffer",
        "data": [
          ...
        ]
    },
    "signingData": [
        {
            "owner": "tnam1qqql82l8d8xcgu8q598gl29vecmelc9v6vfyzwn3",
            "publicKeys": [
                "tpknam1qr4w8d26738k7zmhxhsp9987puunenrjt4kxp5f5k8wlgey3zzuyqg9tgqh"
            ],
            "threshold": 1,
            "accountPublicKeysMap": {
                "type": "Buffer",
                "data": [
                   ...
                ]
            },
            "feePayer": "tpknam1qr4w8d26738k7zmhxhsp9987puunenrjt4kxp5f5k8wlgey3zzuyqg9tgqh"
        }
    ]
}

[euharrison]

LGTM ✅

[jurevans]

Missed this in a previous PR

[mateuszjasiuk]

Tested everything except withdraw as I have to wait 8 hours xD LGTM!