Proposer to propose multiple L2 blocks at once

[ChaitanyaKonda]

#426 adds confirmations for processing L2 events. This will slow block assembly. We should be able to modify conditionalMakeBlock to create numberOfUnprocessedTransactions / TRANSACTIONS_PER_BLOCK blocks instead of just 1. This should allow us to build multiple blocks before having to process the events with their 12 confirmation wait in 0th queue.

[ChaitanyaKonda]

Once the current proposer changes, the new current proposer can submit multiple blocks at once.

• If there are not enough unprocessed transactions for more than 1 block: it is similar to proposing 1 block at a time -> for each L2 block proposal, it will have to wait for prior events in the queue to be processed with their 12 confirmation wait included.
• If there are too many unprocessed transactions: an upper limit for maximum number of L2 blocks to propose is required such that the proposer does not lose gas on all the L2 blocks that did not make it to L1 when they were the current proposer. MAX_L2_BLOCKS_TO_PROPOSE = Number of L1 blocks a proposer gets * the number of L2 blocks can fit in each L1. This assumes that L1 blocks are completely filled with NF's L2 block proposed transactions, this might need to be corrected by a factor