Support IList as a data provider for TableView.

[tznind]

Refactoring TableView to use a new interface ITableDataSource instead of System.Data.DataTable.

Interface would be something like

interface ITableDataSource
{
    int Rows { get; }
    int Columns { get; }
    string[] ColumnNames { get; }
    object this[int row, int col]
    {
        get;
    }
}

This will be breaking but we are working on v2 I think we should consider it as its a nice feature and it is quite a common use case (to use arbitrary objects as the table data items).

That is the approach taken in TermKit and looks like it will make TableView much more flexible:

/// Protocol that describes a matrix made up of columns and rows, where the columns can be labeled
public protocol DataSource {

https://github.com/migueldeicaza/TermKit/blob/main/Sources/TermKit/Views/DataTable.swift

The Goal

The more I look at it, the more I'm excited about the idea.

Check this out! How cool would it be for an API user to be able to do something like:

var s = new EnumerableTableDataSource<Process>(Process.GetProcesses(),
    new()
    {
        { "Name",(p)=>p.ProcessName},
        { "Id",(p)=>p.Id},
        { "HasExited",(p)=>p.HasExited},
    });

myTableView.Table = s;

The EnumerableTableDataSource<T> class definition would be something like:

class EnumerableTableDataSource<T> : ITableDataSource
{
    private T[] data;
    private string[] cols;
    private Dictionary<string, Func<T, object>> lamdas;

    public EnumerableTableDataSource(IEnumerable<T> data, Dictionary<string, Func<T,object>> columnDefinitions)
    {
        this.data = data.ToArray();
        this.cols = columnDefinitions.Keys.ToArray();
        this.lamdas = columnDefinitions;
    }

    public object this[int row, int col]
    {
        get => this.lamdas[ColumnNames[col]](this.data[row]);
    }

    public int Rows => data.Length;

    public int Columns => cols.Length;

    public string[] ColumnNames => cols;
}

Originally posted by @tznind in #2573 (comment)

[tznind]

I've started this refactor in https://github.com/tznind/gui.cs/tree/refactor-tv