[checkpoints] Data execution and reconfiguration entrypoint

[williampsmith]

[WIP]

Introduce component CheckpointExecutor for active checkpoint execution on full nodes and validators.

• CheckpointExecutor subscribes to StateSync channel for newly synced checkpoints
• Feeds checkpoint transactions to TransactionManager and waits on notify for persisted transaction effects
• Tracks checkpoint epoch boundaries and kicks off reconfiguration when necessary
• As a first pass, in current formulation, data execution runs as a single task that executes checkpoints serially, however can/should be augmented down the line to schedule multiple checkpoints for execution, provided they are all within the same (current) epoch.
• Note this PR does not yet start the active process. Will be wired up to SuiNode in a separate PR