Add an integration test for duplicate signers on the same network

[jferrant]

We should have a test that spins up multiple signers with the same private key and ensure the system can handle signatures from duplicate signers. The first submitted valid signature should take precedence.

[jbencin]

Also, check that duplicate signer produces identical signatures, and recovered pubkeys are the same. This is expected because we derive the ECDSA nonce from the message hash instead of an RNG

[jcnelson]

Can we close this?

[jbencin]

Closed by #5108

[blockstack-devops]

This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.