Add base and priority fee to gas oracle response

[sl1depengwyn]

Closes #9201

Changelog

• Calculate the base fee of the next block by ourselves instead of query the node

• Added EIP_1559_BASE_FEE_MAX_CHANGE_DENOMINATOR env variable with default value of 8 to accomplish the task above (Add EIP_1559_BASE_FEE_MAX_CHANGE_DENOMINATOR docs#235)

• Added base and proirity fee

Response example:

{
    "average_block_time": 15030.0,
    "coin_price": null,
    "coin_price_change_percentage": null,
    "gas_price_updated_at": "2024-01-19T21:06:35.462186Z",
    "gas_prices": {
        "average": {
            "base_fee": 23.6,
            "fiat_price": null,
            "price": 23.85,
            "priority_fee": 0.26,
            "time": 15030.0
        },
        "fast": {
            "base_fee": 23.6,
            "fiat_price": null,
            "price": 25.18,
            "priority_fee": 1.59,
            "time": 15030.0
        },
        "slow": {
            "base_fee": 23.6,
            "fiat_price": null,
            "price": 23.64,
            "priority_fee": 0.05,
            "time": 15030.0
        }
    },
    "gas_prices_update_in": 32000,
    "gas_used_today": "0",
    "market_cap": "0",
    "network_utilization_percentage": 33.13972293333333,
    "static_gas_price": null,
    "total_addresses": "177985",
    "total_blocks": "4405",
    "total_gas_used": "0",
    "total_transactions": "300805",
    "transactions_today": "0",
    "tvl": null
}

Checklist for your Pull Request (PR)

• I added an entry to CHANGELOG.md with this PR
• If I added new functionality, I added tests covering it.
• If I fixed a bug, I added a regression test to prevent the bug from silently reappearing again.
• I checked whether I should update the docs and did so by submitting a PR to https://github.com/blockscout/docs
• If I added/changed/removed ENV var, I submitted a PR to https://github.com/blockscout/docs to update the list of env vars at https://github.com/blockscout/docs/blob/master/for-developers/information-and-settings/env-variables.md and I updated the version to master in the Version column. Changes will be reflected in this table: https://docs.blockscout.com/for-developers/information-and-settings/env-variables.
• If I add new indices into DB, I checked, that they are not redundant with PGHero or other tools

[vbaranov]

Why should we check non-nil base_fee here?

[sl1depengwyn]

If we have no base fee, priority fee may be misleading to the user since the price would be calculated without base fee knowledge and there may be strange relations between the price and priority fee, so I decided that it's better not to give priority fee if we do not have base fee by some reason (that is much less probable with manual calculation of the next block base fee)

[sl1depengwyn]

I suggest to fix dialyzer errors in this PR: #8851

[nikitosing]

Let's rename base_fee to base_fee_per_gas here and above