[batch-submitter]: gas optimization / Change groupedBlocks array from many to one element for gas optimization

[guoshijiang]

Simplify groupedBlocks array to include only one element to reduce gas consumption.

Current calldata of CTC appendSequencerBatch:

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

The above huge calldata includes a context array. And there is an array iteration in appendSequencerBatch.

        for (uint32 i = 0; i < numContexts; i++) {
            BatchContext memory nextContext = _getBatchContext(i);

            // Now we can update our current context.
            curContext = nextContext;

            // Process sequencer transactions first.
            numSequencerTransactions += uint32(curContext.numSequencedTransactions);

            // Now process any subsequent queue transactions.
            nextQueueIndex += uint40(curContext.numSubsequentQueueTransactions);
        }

If it can be optimized into an array with only one element, the later rollup transactions will be much smaller than current rollup transactions and expensive array iteration in smart contract will be avoided, which might significantly reduce rollup gas consumption.

According to our analysis, after optimization, each batch rollup transaction will reduce 1/18 to 1/6 gas consumption