Osmosis v12 Oxygen Upgrade

Osmosis v12 Oxygen Upgrade\n\nThis is a proposal to do a software upgrade to the v12.0.0 software tag of the Osmosis codebase on block height 6246000, which is estimated to occur on Friday September 30th, UTC 16:00. Block times have high variance, so please monitor the chain for more precise time estimates.\n\n## Upgrade Features\nThis upgrade adds the following features:\n\n### TWAP\n\n* Time weighted average prices for all AMM pools have been implemented. \n* These expose an on-chain oracle for each pool allowing CosmWasm apps to use this data.\n\n### CosmWasm contract developer features\n\n* Enables select queries for cosmwasm contracts.\n* Adds message responses to gamm messages, to remove the neccessity of bindings.\n* Allow specifying denom metadata from tokenfactory.\n* Upgrade to wasmd v0.28.0\n\n### Interchain Accounts Enabled\n\nAllows accounts on another ICA enabled chain to carry out transactions on Osmosis and vice versa.\n\n### Expedited Proposals\n\nAllows governance to have proposals that execute in faster time windows given higher quorums (2/3rds).\n\n Full Change Log\n\n## Getting Prepared for the Upgrade\n\nAs always, we recommend validators utilize 64GB of RAM. Since state migration is relatively negligible in this upgrade, it is likely possible to get away with less, but still not recommended. If you are unable to have 64GB of RAM, at a minimum have a total of 64GB of swap set to prevent out of memory errors.\n\nIf using cosmovisor, manually build & copy the osmosisd binary to /cosmovisor/upgrades/v12/bin/.\n\nIf not using cosmovisor, wait for your node to halt at the upgrade height, then install and run the v12.0.0 binary.\n\n\n## Details of Upgrade Time\n\nThe proposal targets the upgrade proposal block to be 6246000, anticipated to be on Friday September 30th, UTC 16:00. Note that block times have high variance, so keep monitoring the time. See countdown here.\n\nThe upgrade is anticipated to take approx 30 minutes, during which time, there will not be any on-chain activity on the network.\n\nIn the event of an issue at upgrade time, we should coordinate via the validators channel in discord to come to a quick emergency consensus and mitigate any further issues.