Added Java type Config Object to get chart URL instead of providing non-formatted json string

[nimxch]

If user want to provide your Chart.js config in a neat manner instead of doing all the string formatting, you can use getUrlV2()

Example:

// Instanciate ChartConfig object
ChartConfig config = new ChartConfig();

// Set the char type. e.g bar, line etc
config.setType("bar");
//Instantiate ChartData
ChartData data = new ChartData();
// Set the labels and chart Data
data.setLabels(List.of("Q1", "Q2", "Q3", "Q4"));  //labels

//Dataset 1
Dataset dataset = new Dataset();
dataset.setLabel("Users");
dataset.setData(List.of("50", "60", "70", "180"));

//Dataset 2
Dataset dataset2 = new Dataset();
dataset2.setLabel("Revenue");
dataset2.setData(List.of("100", "200", "300", "400"));

//Set the required Data
data.setDatasets(List.of(dataset, dataset2));
config.setData(data);
chart.setChartConfig(config);

//get the URL
chart.getUrlV2()