file-level constants and free functions not supported

[gitpusha]

Hi,

The plugin doesnt seem to support formatting for solidity file-level constants or functions like these ones:

// SPDX-License-Identifier: UNLICENSED
pragma solidity 0.7.4;

import {
    IGelatoGasPriceOracle
} from "../interfaces/Gelato/IGelatoGasPriceOracle.sol";

IGelatoGasPriceOracle constant GELATO_GAS_PRICE_ORACLE = IGelatoGasPriceOracle(0x169E633A2D1E6c10dD91238Ba11c4A708dfEF37C);

// SPDX-License-Identifier: UNLICENSED
pragma solidity 0.7.4;

import {GELATO_GAS_PRICE_ORACLE} = import "../constants/CGelato.sol";
import {mul} from "../vendor/DSMath.sol";


function _getGelatoGasPrice() view returns (uint256) {
    return uint256(GELATO_GAS_PRICE_ORACLE.latestAnswer());
}

function _getGelatoProviderFees(uint256 _gas) view returns (uint256) {
    return mul(_gas, _getGelatoGasPrice());
}

[fvictorio]

Fixed in #378.