[FEATURE] Monitor external-chain voting of Axelar's vald client

[Pete-LunaNova]

Feature Description

CVMS currently monitors external-chain voting for Axelar's ampd client. This feature introduces monitoring of voting for the vald client.

Reason for Need

Axelar validators run the vald client which votes on the status of transactions on external-chains. Ensuring that this process is functioning correctly is critical.
Enabling CVMS to monitor this and produce prometheus metrics would provide a basis for alerting and make vald easier to maintain for all validators.