Optimistic L2 support

Add Optimistic Rollup L2 (evm) chain support

Possible modifications:

• Which block to consider: Safe or Finalized? (in both situations block is settled on l1, finalized block has less chance of reorg, unsafe blocks are not settled on l1 and are not affected by L1 submission outage)
• Adjusting tx fee calculation (execution and l1 data fee)

Possible scenarios to consider:

• L2 reorg (ex: here)
• Sequencer Outage (similar to chain halt)
• L1 submission outage (blocks are produced on L2 but not settled on L1)
• Invalid block