Increase MaxBlockSize from 200k to 2mb

Hub Proposals
1

In testing pursuant to https://forum.cosmos.network/t/amulet-security-advisory-for-cometbft-asa-2023-002 it’s been clearly found that the current 200kb block size poses a class of risks.

These risks have been explained in the validators private discord, and any validator can reach out to me at https://twitter.com/gadikian to have the issues explained in detail, if need be. Validators needing more information will be added to the Validators Working Group On Spam suggested by Amulet in https://forum.cosmos.network/t/amulet-security-advisory-for-cometbft-asa-2023-002.

Current baseapp BlockParams: 200 kilobytes

gaiad q params subspace baseapp BlockParams | jq

{
  "subspace": "baseapp",
  "key": "BlockParams",
  "value": "{\"max_bytes\":\"200000\"}"
}

Future baseapp BlockParams: 2 megabytes

{
  "subspace": "baseapp",
  "key": "BlockParams",
  "value": "{\"max_bytes\":\"2000000\"}"
}

Validators are encouraged to inquire via the validators working group on spam or by DM to twitter.com/gadikian.