EraE E2E Test & Infra

[svlachakis]

Adds an EraE import/export test.

The test expects a node running with SnapSync on Sepolia.

The flow is quite simple:

1. Wait for node to snap sync
2. Update config with remote import flags (ethpandaops Sepolia store) and restart the node - this could be replaced with our EraE files when we upload them somewhere.
3. Wait for node to finish EraE import
4. Delete the downloaded era files
5. Update config with export flags and restart the node
6. Wait for node to finish EraE export
7. Verify that eth_getBlockByNumber for mergeBlock / 2 returns the same response before and after export