feat: add DA worker

[apoorvsadana]

We previously planned to avoid a DA worker for L2s using Ethereum because the blob is submitted directly during state update. However, we now plan to add this back because it allows for a more generalised design across Alt DA layers and Ethereum. The DA worker will

1. Fetch the last job for which we completed DA
2. Create a DA job for all blocks > last job and <= latest completed block on the chain