[Feature]: Do not return a signature on Stacks txids mismatch

[djordon]

Feature - Do not return a signature on Stacks txids mismatch

1. Description

The signers use a debug assert for checking whether the received txid matches the expected txid before providing a signature for a Stacks transaction. They should instead use a proper error.

1.1 Context & Purpose

After a Stacks transaction has passed validation we should have a proper check for whether the sent txid matches the one that the signer generates locally. If they don't match then they should not send a signature and log the issue. The coordinator is not be able to use the signature anyway -- they don't try, they ignore the signature -- but it's better this way since we can see what is happening.

2. Technical Details:

The signers log an error when there is a Stacks txid mismatch and do not provide a signature.

2.1 Acceptance Criteria:

• The signers log an error when there is a txid mismatch for stacks transactions.
• The signers do not send a signature when when there is a txid mismatch.

3. Related Issues and Pull Requests (optional):

[djordon]

This was fixed in #1165.