maxCodeSizeChangeBlock to genesis for tracking maxCodeSize value change

[vsmk98]

Added maxCodeSizeChangeBlock to track the block number when the maxCodeSize changes from default 24K to the value given.
For long standing networks, it is possible that contracts which crossed default 24k size were deployed at some time and the network rejected the same with max code size exceeded error. If the network at later point changed the maxCodeSize to a higher value and post this if a new node joins the network, the new node will sync the old blocks with the higher max code size value and thus the gas computed on the historical block will be different from the network resulting in bad block error.
maxCodeSizeChangeBlock has been added track the block number where the new maxCodeSize value was set for the network overwriting the default value of 24K. This will ensure that any new nodes joining the network will be able to sync the historical blocks without the bad block error.

However, it should be noted that, if maxCodeSize has been changed several times at network level, maxCodeSizeChangeBlock will only track the last change and for all other prior blocks it will take 24K as the default maxCodeSize. In this scenario, its possible to get the bad blocks error at the time of network sync

#942

[jbhurat]

LGTM

[jpmsam]

if maxCodeSize has been changed several times at network level, maxCodeSizeChangeBlock will only track the last change and for all other prior blocks it will take 24K as the default maxCodeSize.

While this PR fix's the immediate issue, we'll need to look into handling possible multiple maxCodeSizes on the network.

[jimthematrix]

thanks for making this update @vsmk98, we already have a customer that was hit by the issue and can benefit from the enhanced maxCodeSize configuration.

@jpmsam definitely agree having support for multiple settings each tied to a block number would be a very useful next step.

[jiakun9707]

Why not do the same tracking for the transaction size limit?