[Feature]: Simplify stacks transaction signing

[djordon]

Feature - Simplify stacks transaction signing

1. Description

1.1 Context & Purpose

The signers need to collectively sign a stacks transaction before submitting it to the network. To do that, we need to correctly formulate the proper digest. This ticket is to add functionality to make that processes easier (analogous to this: #152)

2. Technical Details:

2.1 Acceptance Criteria:

Stacks does not support Schnorr signatures yet, so the signers need to operate as a multi-sig wallet and authenticate using the appropriate spending conditions for the wallet (details on transaction authorization from SIP-005).

• Add helper functions to simplify the process of signing a stacks transaction.

3. Related Issues and Pull Requests (optional):

Creating a transaction signed by a multi-sig wallet is difficult for stacks transactions in v2.5, since each signature must be generated serially in the proscribed order. But this might change post Nakamoto.

• sBTC Design discussion for multi-sig wallets [Design]: Stacks native multisig wallets for Signer operations #59.
• Stacks SIP draft to support out-of-order signing of transactions for multi-sig addresse/wallets SIP-027: non sequential multisig transactions stacksgov/sips#152.
• PR adding support to stacks-core for out-of-order signing of Stacks transactions Feat: Signature order-independence fix for multisig tx stacks-core#3710.

I hope order-independent-multisig-spending-conditions will land with Nakamoto, but I need to verify. If it does, it will significantly simplify signing Stacks transactions by the signers.