Recognise BUSD as a Stablecoin asset

This proposal would recognise BUSD as a Stablecoin asset on Osmosis.\n\n\nDetails\n\n Proposal 233 defined Stablecoins as an asset type to used in the incentive category structure.\nAssets defined as Stablecoins are currently eligible for:\n* Access to the Osmo/Stable Category for their incentivised pools\n* Access to the Stable/Stable Category for their incentivised pools\n* Automatic matching of External incentives within the Stable/Stable Category as per Proposal 377\n\nIn the wider market, BUSD is currently the USD Stablecoin with the 3rd greatest share of Stablecoin marketcap at ~12%.\nOn Osmosis, BUSD is currently provided canonically via the Axelar bridge, however, this proposal authorises whichever BUSD is authorised as the canonical asset on Osmosis as the stable asset.\n\n\nAbout BUSD\n\nBUSD is a 1:1 USD-backed stablecoin approved by NYDFS and issued by Paxos on Ethereum. Binance provides Binance-Peg BUSD on other chains by locking an equivalent amount of assets on Ethereum. The current version of BUSD in use on Osmosis arrives from Ethereum via the Axelar bridge.\nWebsite: https://paxos.com/busd/\n\n\nCommonwealth Thread: https://commonwealth.im/osmosis/discussion/9344-define-new-stablecoin-assets