feat: add graceful shutdown

[hal3e]

closes: #20

• I added custom Debugs to FuelBlock and FuelBlockCommitedOnEth for better log readability.

[Voxelot]

What about signal handling, ie. like how fuel-core does it:

https://github.com/FuelLabs/fuel-core/blob/7b2f51d1307f24ecc7013a91fb172764b4e4c9bd/bin/fuel-core/src/cli/run.rs#L379

By capturing the stop signal, it will make docker / k8s wait 30s for the service to shut itself down before force-killing it.

[hal3e]

What about signal handling, ie. like how fuel-core does it:

https://github.com/FuelLabs/fuel-core/blob/7b2f51d1307f24ecc7013a91fb172764b4e4c9bd/bin/fuel-core/src/cli/run.rs#L379

By capturing the stop signal, it will make docker / k8s wait 30s for the service to shut itself down before force-killing it.

The axtic web server is listening to SIGINIT and SIGTERM signals. Once they are received and the axtic web server is down, our shutdown_function is called and we signal all our tasks to stop and we wait until they are down.