Sidecar: invalidate past state

[merklefruit]

Block templates should be cleared once a new head for that slot has been received from the CL.
Furthermore, tracked nonces should be only reset if a preconfirmed transaction was successfully included in a block.

bolt/bolt-sidecar/src/state/execution.rs

Line 201 in 6091199

// TODO: invalidate any state that we don't need anymore (will be based on block template)