让Dapper支持Mock

　　Dapper，在.net的ORM中占有一席之地，用法简单，灵活，使用如下。但也带来一个问题，就是在单元测试时，Mock比较难办。

 public List GetAllGoods()
 {
     using var con = new SqlConnection();
     var sql = "select * from Goodses";
     var list = con.Query(sql, new { id = 1 }).ToList();
     return list;
 }

　　mock最好是一个接口，但Dapper是基于IDbConnection做的扩展方法，为了能把这些方法的功能抽出来到一个接口，这里要经过一个设计，来转嫁调用这些扩展方法，具体做法如下：

定义接口IGUIDapper.cs

  /// 

    /// IDapperPlus接口
    /// 
    public interface IDapperPlus
    {
        /// 

        /// 连接
        /// 
        public IDbConnection Connection
        {
            get;
        }

        /// 

        /// Executes a single-row query, returning the data typed as type.
        /// 
        /// The type to return.
        /// The SQL to execute for the query.
        /// The parameters to pass, if any.
        /// The transaction to use, if any.
        /// Whether to buffer results in memory.
        /// The command timeout (in seconds).
        /// The type of command to execute.
        /// A sequence of data of the supplied type; if a basic type(int, string, etc) is queried then the data from the first column in assumed, otherwise an instance is created per row, and a direct column-name===member-name mapping is assumed(case insensitive).
        /// 异常:T:System.ArgumentNullException:type is null.
        /// 
        IEnumerable