[CONSENSUS] Create helper in consensus tests for waiting for FSM events

[gokutheengineer]

Objective

Create a helper function for waiting for FSM events in consensus tests.

Origin Document

Goals

• Ensure state sync tests show deterministic behavior.

Deliverable

• Helper function WaitForFSMEvents for consensus tests.

Non-goals / Non-deliverables

• Change business logic

General issue deliverables

• Update the appropriate CHANGELOG(s)
• Update any relevant local/global README(s)
• Update relevant source code tree explanations
• Add or update any relevant or supporting mermaid diagrams

Testing Methodology

• All tests: make test_all
• LocalNet: verify a LocalNet is still functioning correctly by following the instructions at docs/development/README.md

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Creator: @gokutheengineer
Co-Owners: @Olshansk

[Olshansk]

@gokutheengineer I think this is a priority over leader election.

It could also be good candidate for the "shared testing utilities" @bryanchriswhite is working on.

[Olshansk]

As we will likely be removing the FSM, I'm closing this out for now