FormsPlot: `MouseEnter` and `MouseLeave` events not getting fired

[CD-SailingPerf]

Issue:
MouseEnter and MouseLeave events not getting fired.
This may have worked at some point according to this issue, but it now seems broken.
#999

ScottPlot Version: 5.0.34

Code Sample:

            ScottPlot.WinForms.FormsPlot frmPl = new ScottPlot.WinForms.FormsPlot();
            this.Controls.Add(frmPl);
            frmPl.Dock = System.Windows.Forms.DockStyle.Fill;
            frmPl.MouseEnter += (s, ev) =>
            {
                MessageBox.Show("Mouse enter");
            };
            frmPl.MouseLeave += (s, ev) =>
            {
                MessageBox.Show("Mouse leave");
            };
            frmPl.Refresh();