[stacks-signer] construct rejection stx transaction

[jferrant]

Description

Create a function that constructs a rejection stx transaction call for a specific txid (either BTC or STX txid)

Context

If signers reach quorum but to reject a specific deposit or withdrawal, they need to prove that they were in agreement and do not want to deposit or withdraw.

Expected Approach

Create a function that constructs a "reject_request" clarity function that takes a BTC txid or STX txid as input. The resulting signature over this will prove quorum was reached to that effect.

Acceptance Criteria

• PR adds the feature ...