feat: Add support for gas payment expressed in a non-native tokens

[ameten]

Issue

Unknown cryptocurrency for gas payment

Intro

InterchainGasPaymaster smart contract does not provide the cryptocurrency in which it expresses gas payment. It can be wei for Ethereum, inj for Injective and TIA for Neutron.

As the result, Scraper does not know how it can convert the gas payment into the fundamental unit of the cryptocurrency.

Change

1. InterchanGasPaymaster should provide cryptocurrency in gas_payment event.
2. Scraper should be able to read this data and record it into gas_payment table.
3. Explorer should be able to render the unit of gas payment correctly.