Add CancellationToken support for MultiMap Queries.

[Rendojack]

Add overload methods for MultiMap queries to pass CancellationToken to CommandDefinition.

From this:

public static IEnumerable<TReturn> Query<TReturn>(this IDbConnection cnn, string sql, Type[] types, Func<object[], TReturn> map, object? param = null, IDbTransaction? transaction = null, bool buffered = true, string splitOn = "Id", int? commandTimeout = null, CommandType? commandType = null)
{
    var command = new CommandDefinition(sql, param, transaction, commandTimeout, commandType, buffered ? CommandFlags.Buffered : CommandFlags.None);
    var results = MultiMapImpl(cnn, command, types, map, splitOn, null, null, true);
    return buffered ? results.ToList() : results;
}

To this:

public static IEnumerable<TReturn> Query<TReturn>(this IDbConnection cnn, string sql, Type[] types, Func<object[], TReturn> map, object? param = null, IDbTransaction? transaction = null, bool buffered = true, string splitOn = "Id", int? commandTimeout = null, CommandType? commandType = null, CancellationToken ct = CancellationToken.None)
{
    var command = new CommandDefinition(sql, param, transaction, commandTimeout, commandType, buffered ? CommandFlags.Buffered : CommandFlags.None, ct);
    var results = MultiMapImpl(cnn, command, types, map, splitOn, null, null, true);
    return buffered ? results.ToList() : results;
}

EDIT:

Another aproach would be to give access to some private methods like: MultiMapImpl where we could manually build CommandDefinition with CancellationToken assigned to it.