Fee market for cross-chain transactions

[bbbeeeee]

The protocol currently has flat fee parameters for cross-chain messaging and omnichain smart contracts:

• https://www.zetachain.com/docs/developers/cross-chain-messaging/gas-fees/
• https://www.zetachain.com/docs/developers/omnichain/gas-fees/

Long-term, I think it would be ideal to have some sort of gas-like fee market that can help throttle the network and offer a more dynamic system versus the flat fee which may sometimes be prohibitive or too rigid.