POC: Support blocks with blob txs

[halo3mic]

About

• This is POC for building blocks with blob transactions.
• Relates to PR POC: Build blocks with blob txs suave-execution-geth#18
• For testing purposes it includes sending block to relay while block building - this should be removed

Example of successful blocks with this version (and related external PR)

• 10543547 see beacon explorer for 5 included blobs here
• 10543699 see beacon explorer for 5 included blobs here

[halo3mic]

What I noticed is that BUILD_ETH_BLOCK precompile always reverts with no error msg for some reason and the block was never included on-chain. I suspected that this could be gaslimit issue due to the size of blobs and put this snippet in buildEthBlock. Now the precompile still reverts, like before, but the block is included on-chain like the example blocks in the previous comment.

res, err := b.submitEthBlockToRelay("https://0xafa4c6985aa049fb79dd37010438cfebeb0f2bd42b115b89dd678dab0670c1de38da0c4e9138c9290a398ecd9a0b3110@boost-relay-goerli.flashbots.net", bidBytes)
if err != nil {
    return nil, nil, fmt.Errorf("could not submit block to relay: %w", err)
}
log.Info("submitted block to relay", "response", string(res))

The snippet only serves for testing purposes and should be removed. Likewise, this snippet is not needed if gaslimit of local client is raised sufficiently, however didn't have any luck doing that.