Control of max_gas and max_bytes

[haasted]

Osmosis recently had a governance proposal to change the max_gas and max_bytes parameters, in order to allow for more transactions and bigger blocks : https://wallet.keplr.app/#/osmosis/governance?detailId=4

This chain does not use the governance module, so we need to look into alternative ways to be able to control parameters such as these.

Also, we should look into having defaults that resemble the ones chosen by the Osmosis chain.

[blewater]

They have included the governance module to manage parameters github.com/osmosis-labs/osmosis/app.go#L355 but didn't see in practice whether they use it.
With our upgrade work and the upcoming v0.43 in-place store migrations https://docs.cosmos.network/master/core/upgrade.html we should be able to achieve that.