[Core] Support of an adjustment coefficient for the gas price

[thomas-nguy]

• Current code only support ETH as native currency for L2, it relied on the gas_adjustement package to define how much we are okay to pay for the L1 transaction

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

Tasks involve :

• Create a new table or update existing table in DB to store the coefficient value (CRUD db functions need to be supported by the utility module). The value will be updated by the oracle service ([Core] Development of an oracle service #16)

• Modify the l1_gas_price package and any reference to the gas_price (in web3 api endpoint) to be sure to multiple by the coefficient factor when fetching the gas price

• Perform minimal changes is required to avoid diverging with upstream