Add ability to add charts to WordParagraph

[PrzemyslawKlys]

This PR fixes:

• Insert charts in paragraphs #143
• It allows to add chart to existing paragraph (before it was only possible to assign chart to document).
• WordParagraph now contains IsChart and Chart object
• WordDocument and WordSection contains ParagraphsCharts and Charts lists

public static void Example_AddingMultipleCharts(string folderPath, bool openWord) {
    Console.WriteLine("[*] Creating standard document with charts");
    string filePath = System.IO.Path.Combine(folderPath, "Charts Document.docx");

    using (WordDocument document = WordDocument.Create(filePath)) {
        List<string> categories = new List<string>() {
            "Food", "Housing", "Mix", "Data"
        };

        var paragraphToTest = document.AddParagraph("Test showing adding chart right to existing paragraph");

        // adding charts to document
        document.AddParagraph("This is a bar chart");
        var barChart1 = document.AddBarChart();
        barChart1.AddCategories(categories);
        barChart1.AddChartBar("Brazil", new List<int>() { 10, 35, 18, 23 }, SixLabors.ImageSharp.Color.Brown);
        barChart1.AddChartBar("Poland", new List<int>() { 13, 20, 230, 150 }, SixLabors.ImageSharp.Color.Green);
        barChart1.AddChartBar("USA", new[] { 10, 35, 18, 23 }, SixLabors.ImageSharp.Color.AliceBlue);
        barChart1.BarGrouping = BarGroupingValues.Clustered;
        barChart1.BarDirection = BarDirectionValues.Column;

        Console.WriteLine("Charts count: " + document.Sections[0].Charts.Count);

        document.AddParagraph("This is a bar chart");
        var barChart2 = document.AddBarChart();
        barChart2.AddCategories(categories);
        barChart2.AddChartBar("USA", 15, Color.Aqua);
        barChart2.RoundedCorners = true;


        Console.WriteLine("Charts count: " + document.Sections[0].Charts.Count);

        document.AddParagraph("This is a pie chart");
        var pieChart = document.AddPieChart();
        pieChart.AddCategories(categories);
        pieChart.AddChartPie("Poland", new List<int> { 15, 20, 30 });

        Console.WriteLine("Charts count: " + document.Sections[0].Charts.Count);


        document.AddParagraph("Adding a line chart as required 1");

        var lineChart = document.AddLineChart();
        lineChart.AddChartAxisX(categories);
        lineChart.AddChartLine("USA", new List<int>() { 10, 35, 18, 23 }, SixLabors.ImageSharp.Color.AliceBlue);
        lineChart.AddChartLine("Brazil", new List<int>() { 10, 35, 300, 18 }, SixLabors.ImageSharp.Color.Brown);
        lineChart.AddChartLine("Poland", new List<int>() { 13, 20, 230, 150 }, SixLabors.ImageSharp.Color.Green);

        Console.WriteLine("Charts count: " + document.Sections[0].Charts.Count);

        document.AddParagraph("Adding a line chart as required 2");

        var lineChart2 = document.AddLineChart();
        lineChart2.AddChartAxisX(categories);
        lineChart2.AddChartLine("USA", new List<int>() { 10, 35, 18, 23 }, SixLabors.ImageSharp.Color.AliceBlue);
        lineChart2.AddChartLine("Brazil", new List<int>() { 10, 35, 300, 18 }, SixLabors.ImageSharp.Color.Brown);
        lineChart2.AddChartLine("Poland", new List<int>() { 13, 20, 230, 150 }, SixLabors.ImageSharp.Color.Green);

        Console.WriteLine("Charts count: " + document.Sections[0].Charts.Count);

        // adding charts to paragraphs directly
        var paragraph = document.AddParagraph("This is a bar chart - but assigned to paragraph 1");
        var barChart3 = paragraph.AddBarChart();
        barChart3.AddCategories(categories);
        barChart3.AddChartBar("Brazil", new List<int>() { 10, 35, 18, 23 }, SixLabors.ImageSharp.Color.Brown);
        barChart3.AddChartBar("Poland", new List<int>() { 13, 20, 230, 150 }, SixLabors.ImageSharp.Color.Green);
        barChart3.AddChartBar("USA", new[] { 10, 35, 18, 23 }, SixLabors.ImageSharp.Color.AliceBlue);
        barChart3.BarGrouping = BarGroupingValues.Clustered;
        barChart3.BarDirection = BarDirectionValues.Column;

        Console.WriteLine("Charts count: " + document.Sections[0].Charts.Count);

        var paragraph1 = document.AddParagraph("This is a bar chart - but assigned to paragraph 2");
        var barChart5 = paragraph1.AddBarChart();
        barChart5.AddCategories(categories);
        barChart5.AddChartBar("USA", 15, Color.Aqua);
        barChart5.RoundedCorners = true;

        Console.WriteLine("Charts count: " + document.Sections[0].Charts.Count);

        var paragraph2 = document.AddParagraph("This is a pie chart - but assigned to paragraph");
        var pieChart1 = paragraph2.AddPieChart();
        pieChart1.AddCategories(categories);
        pieChart1.AddChartPie("Poland", new List<int> { 15, 20, 30 });

        var paragraph3 = document.AddParagraph("Adding a line chart as required 1 - but assigned to paragraph");
        var lineChart3 = paragraph3.AddLineChart();
        lineChart3.AddChartAxisX(categories);
        lineChart3.AddChartLine("USA", new List<int>() { 10, 35, 18, 23 }, SixLabors.ImageSharp.Color.AliceBlue);
        lineChart3.AddChartLine("Brazil", new List<int>() { 10, 35, 300, 18 }, SixLabors.ImageSharp.Color.Brown);
        lineChart3.AddChartLine("Poland", new List<int>() { 13, 20, 230, 150 }, SixLabors.ImageSharp.Color.Green);

        Console.WriteLine("Charts count: " + document.Sections[0].Charts.Count);

        var paragraph4 = document.AddParagraph("Adding a line chart as required 2 - but assigned to paragraph");
        var lineChart4 = paragraph4.AddLineChart();
        lineChart4.AddChartAxisX(categories);
        lineChart4.AddChartLine("USA", new List<int>() { 10, 35, 18, 23 }, SixLabors.ImageSharp.Color.AliceBlue);
        lineChart4.AddChartLine("Brazil", new List<int>() { 10, 35, 300, 18 }, SixLabors.ImageSharp.Color.Brown);
        lineChart4.AddChartLine("Poland", new List<int>() { 13, 20, 230, 150 }, SixLabors.ImageSharp.Color.Green);

        Console.WriteLine("Charts count: " + document.Sections[0].Charts.Count);

        // lets add chart to first paragraph
        var lineChart5 = paragraphToTest.AddLineChart();
        lineChart5.AddChartAxisX(categories);
        lineChart5.AddChartLine("USA", new List<int>() { 10, 35, 18, 23 }, SixLabors.ImageSharp.Color.AliceBlue);
        lineChart5.AddChartLine("Brazil", new List<int>() { 10, 35, 300, 18 }, SixLabors.ImageSharp.Color.Brown);
        lineChart5.AddChartLine("Poland", new List<int>() { 13, 20, 230, 150 }, SixLabors.ImageSharp.Color.Green);

        Console.WriteLine("Charts count: " + document.Sections[0].Charts.Count);

        var table = document.AddTable(3, 3);
        table.Rows[0].Cells[0].Paragraphs[0].AddBarChart();
        barChart3.AddCategories(categories);
        barChart3.AddChartBar("Brazil", new List<int>() { 10, 35, 18, 23 }, SixLabors.ImageSharp.Color.Brown);
        barChart3.AddChartBar("Poland", new List<int>() { 13, 20, 230, 150 }, SixLabors.ImageSharp.Color.Green);
        barChart3.AddChartBar("USA", new[] { 10, 35, 18, 23 }, SixLabors.ImageSharp.Color.AliceBlue);
        barChart3.BarGrouping = BarGroupingValues.Clustered;
        barChart3.BarDirection = BarDirectionValues.Column;

        Console.WriteLine("Charts count: " + document.Sections[0].Charts.Count);

        Console.WriteLine("Images count: " + document.Sections[0].Images.Count);

        document.Save(openWord);
    }
}