[Core] Development of an oracle service

[thomas-nguy]

• Need to define how the gas token price can be fetched (where the token will be listed)
• Create a system that will fetch the price of the gas token and ETH at continuous interval
• Compare the price of the gas token with eth and update the adjustement coefficient in the DB

[thomas-nguy]

we may just modify the gas_adjuster project instead

https://github.com/cronos-labs/zksync-era/tree/internal/core/bin/zksync_core/src/l1_gas_price/gas_adjuster

however it depends how the token price will be fetched (if its DEX or CEX, we may need to develop a separate service)

[thomas-nguy]

Most likely, the gas token contract will be listed on uniswap (main source of liquidity)