Cursor position not updating correctly in TextField

[YourRobotOverlord]

Describe the bug
Cursor position not updating correctly in file dialog path field when the path is wider than the field width.

To Reproduce
Steps to reproduce the behavior:

1. Open a SaveDialog
2. Type in path field until input scrolls
3. Cursor is no longer visually located at the end of the text - typed characters are still appended to path string, however.

Screenshots

[tznind]

@BDisp this seems to be generic problem with TextField rather than a problem with file dialog itself.

I have created a draft PR with a test showing the problem (see below for brevity). Any idea how we fix it @BDisp? :

[Theory]
[ClassData (typeof (V2TestDrivers))]
public void TextField_Cursor_AtEnd_WhenTyping (V2TestDriver d)
{
    // Simulates typing abcd into a TextField with width 3 (wide enough to render 2 characters only)
    using var c = With.A<Window> (100, 20, d)
                      .Add (new TextField () { Width = 3 })
                      .Focus<TextField> ()
                      .WaitIteration ()
                      .AssertCursorPosition (new Point (1, 1)) // Initial cursor position (because Window has border)
                      .RaiseKeyDownEvent (Key.A)
                      .WaitIteration ()
                      .ScreenShot ("After typing first letter", _out)
                      .AssertCursorPosition (new Point (2, 1)) // Cursor moves along as letter is pressed
                      .RaiseKeyDownEvent (Key.B)
                      .WaitIteration ()
                      .AssertCursorPosition (new Point (3, 1)) // Cursor moves along as letter is pressed
                      .RaiseKeyDownEvent (Key.C)
                      .WaitIteration ()
                      .ScreenShot ("After typing all letters",_out)

// This is where test fails (you can test by commenting out this and next assert and see it then passes)
                      .AssertCursorPosition (new Point (3, 1)) // Cursor stays where it is because we are at end of TextField
                      .RaiseKeyDownEvent (Key.D)
                      .WaitIteration ()
                      .ScreenShot ("Typing one more letter", _out)

// This currently also fails as the cursor moves backwards
                      .AssertCursorPosition (new Point (3, 1)) // Cursor still stays at end of TextField
                      .WriteOutLogs (_out)
                      .Stop ();
}