[Consensus] Remove the dependency of state sync on the FSM

[Olshansk]

Objective

Remove the dependency of state sync on the FSM.

Origin Document

While working on #352, it became evident that the Finite State Machine adds complexity to the implementation and understanding of state sync rather than simplify it.

Goals

• Reduce the complexity of the codebase
• Reduce cognitive load on future owners of the state sync submodule
• Make future optimizations of state sync simpler
• Decouple state sync logic from the larger scope of the node operations
• Prepare the codebase to remove the FSM

Deliverable

• Remove all technical relationships, constants, variables, interfaces, etc between state sync and the FSM
• Updated documentation that remove all relationships between State Sync and the FSM
• Follow up GitHub tickets to remove the FSM altogether

Non-goals / Non-deliverables

• Removing the FSM from the codebase
• Further optimizations to state sync

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

• Task specific tests or benchmarks: make ...
• New tests or benchmarks: make ...
• All tests: make test_all
• LocalNet: verify a LocalNet is still functioning correctly by following the instructions at docs/development/README.md
• k8s LocalNet: verify a k8s LocalNet is still functioning correctly by following the instructions here

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Creator: @Olshansk