Create Data structure

[AppPear]

v2 ticket

Ticket description:

This should hold and handle the values for charts. You should create it in a way that changes in the source data can be automatically reflected in the charts.

• should be a structure which can hold a x and y value.
• y value must be numeric (possibly floating point number)
• x can be numeric or string
• has to be at least 3 initialisers: 1) only y values, 2) x and y numeric values 3) x string and y numeric values
• changes in the source are reflected in the charts automatically

More info: #89

[satan87]

I did a simple test.

import SwiftUI
import SwiftUICharts

struct ContentView: View {
    
    @State var data: [Double] = [1, 2, 3]
    
    var body: some View {
        
        VStack {
            
            CardView {
                ChartView(data: self.data)
                ChartLabel("Test \(self.data[0])")
            }
            
            Button(action: {
                self.data[0] += 1
                print(self.data[0])
            }) {
                Text("Click to add")
            }
        
        }
    }
}

I can see the value of the ChartLabel being updated.
But the graph is not being updated...

I manage to have the BarCell, and BarChart update using Binding for the value instead of State.
But still, when using ChartView, there is no update.

Should we use @EnvironmentObject, and move to somehing like this:
ChartView().environmentObject(DataControler(Data: [1,2,3]))

[satan87]

PR #112
I manage to arrive at the result by using Binding, all the way.