Replacement character for C0 control characters is measured wrong

[pjanx]

Checklist

• I have searched the issue tracker for open issues that relate to the same problem, before opening a new one.
• This issue only relates to a single bug. I will open new issues for any other problems.

Describe the bug

C0 replacement characters are rendered differently than their size is measured for cursor rendering.
Independent of platform.

How to reproduce

• Run the example code
• Select the Entry, whose cursor is already at the end
• Move the cursor to the left using your keyboard and observe

Screenshots

Example code

package main

import (
	"net"

	"fyne.io/fyne/v2"
	"fyne.io/fyne/v2/app"
	"fyne.io/fyne/v2/dialog"
	"fyne.io/fyne/v2/driver/mobile"
	"fyne.io/fyne/v2/widget"
)

func main() {
	a := app.New()
	w := a.NewWindow("Bugs")
	w.Resize(fyne.NewSize(640, 480))
	w.SetContent(widget.NewMultiLineEntry())

	connectAddress := widget.NewEntry()
	connectAddress.SetPlaceHolder("host:port")
	connectAddress.Validator = func(text string) error {
		_, _, err := net.SplitHostPort(text)
		return err
	}
	connectAddress.SetText(string([]byte{3, 2, 1, 65, 66, 67, ':', '1'}))
	connectAddress.TypedKey(&fyne.KeyEvent{Name: fyne.KeyPageDown})

	var wConnect *dialog.FormDialog
	wConnect = dialog.NewForm("Connect to relay", "Connect", "Exit",
		[]*widget.FormItem{
			{Text: "Address:", Widget: connectAddress},
		}, func(ok bool) {
			if ok {
			} else if _, ok := a.Driver().(mobile.Driver); ok {
				wConnect.Show()
			} else {
				a.Quit()
			}
		}, w)
	wConnect.Show()
	w.ShowAndRun()
}

Fyne version

2.5.2

Go compiler version

1.23.2

Operating system and version

Linux

Additional Information

No response

[andydotxyz]

I think that actually the measurement for cursor is correct and the advancing in render is wrong because they should be better spaced out than in the screenshot.