feat: create IVersion interface

[ihoroleksiienko]

Main changes

A new IVersion interface has been introduced to provide structured versioning of smart contracts.

/**
 * @title IVersion interface
 * @author CloudWalk Inc. (See https://cloudwalk.io)
 * @dev Defines the function to get the contract version.
 */
interface IVersion {
    /**
     * @dev The struct for the contract version.
     */
    struct Version {
        uint8 major; // -- The major version of contract
        uint8 minor; // -- The minor version of contract
        uint8 patch; // -- The patch version of contract
    }

    /**
     * @dev Returns the version of the contract.
     */
    function $__VERSION() external pure returns (Version memory);
}

Test coverage

New functionality was fully covered by tests.