Consider an object overload for SqlServerDbFunctionsExtensions

[ajcvickers]

We currently have the following overloads:

        public static int? DataLength(this DbFunctions _, string arg)
        public static int? DataLength(this DbFunctions _, bool? arg)
        public static int? DataLength(this DbFunctions _, double? arg)
        public static int? DataLength(this DbFunctions _, decimal? arg)
        public static int? DataLength(this DbFunctions _, DateTime? arg)
        public static int? DataLength(this DbFunctions _, TimeSpan? arg)
        public static int? DataLength(this DbFunctions _, DateTimeOffset? arg)
        public static int? DataLength(this DbFunctions _, byte[] arg)
        public static int? DataLength(this DbFunctions _, Guid? arg)

The main use case for an object overload is when a value converter is being used in the model such that the type in the application is not one of the types above, but the type in the database is still something that DATALENGTH can be called with.

[ajcvickers]

The same may be true for other methods here, such as the DateDiff overloads.