[builder] Limit storage slots to check in eth_sendRawTransactionConditional

[dancoombs]

Describe the feature
Both Optimism and Arbitrum limit the number of storage slots or known accounts (respectively) that you can send to eth_sendRawTransactionConditional. Rundler needs to adhere to this limit by limiting the size of a bundle when it goes over this number of slots. We should, however, try to make the largest bundle possible.