review globalfee and txfees modules

[mtsitrin]

Review the following modules, decide whether relevant to the rollapp use case

https://github.com/cosmos/gaia/blob/main/docs/modules/globalfee.md https://github.com/osmosis-labs/osmosis/tree/main/x/txfees

[mtsitrin]

@shaolin-flow Current method for minimum supported fees is by defining "min_gas_prices" at validator's node.

Regarding GlobalFee module:

• Allows to have "global" fees requirement, across all validator nodes
• The "min_gas_prices" of the validator can have "harder" requirement

Regarding txfees module:

• As above, allows to set multiple tokens for fees. Globally validated.
• Different from above, the fees paid are swapped to the base denom

IMO, those modules are not required for a rollapp:

• We'll have single/few sequencers. Not sure the GlobalFee validation is required. fees can be enforced using sequencer's "min_gas_prices" param

let me know what u think

[shaolin-flow]

Agreed these are not required for the RDK. As such, closing this issue.