This PR moves kzg commitments to bid. The rationale behind is captured
in this [issue](https://github.com/ethereum/consensus-specs/issues/4870)
* Moves blob KZG commitments to the earlier point where builder intent
is known
* Removes duplicated commitments from data column sidecars which saves
descent b/w per slot
* Enables nodes to start fetching blobs via getBlobs as soon as the bid
is received
* Slightly increases bid size and may add minor bidding channel latency
but the tradeoff favors lower network load and simpler DA handling
14f01bbc6c