Simplify universal verification function (das branch)

[asn-d6]

The "Compute sum of commitments" code can be simplified by just doing an MSM over all commitments and their weights. That is, without sieving which are used and which are not which IMO complicates the codebase. Anything that is not used would have zero weight and hence it would not contribute to the MSM.

This is what @b-wagn did in his PR (ethereum/consensus-specs#3812) and it's simpler.

After all, if I'm not mistaken, for PeerDAS we will always use all the commitments since we fetch the entire column, so we will not do any wasted bytes_to_kzg_commitment().

[asn-d6]

Implemented by Justin in 47bb90d