moved DecimalsConverter to utils (#75)

Author: Arvolear

contracts/libs/decimals/DecimalsConverter.sol renamed to contracts/libs/utils/DecimalsConverter.sol

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.4;
 
-import {DecimalsConverter} from "../../../libs/decimals/DecimalsConverter.sol";
+import {DecimalsConverter} from "../../../libs/utils/DecimalsConverter.sol";
 import {IERC20Metadata} from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
 
 contract DecimalsConverterMock {