Toolbar with widget.Label makes the ToolbarAction buttons higher

[marmiha]

Describe the bug:

Adding a widget.NewLabel() inside a widget.NewToolbar() makes the widget.NewToolbarAction() a little bit higher.

To Reproduce:

Steps to reproduce the behaviour:

1. Make a custom struct inheriting widget.ToolbarItem

type toolbarLabel struct {
	*widget.Label
}

func NewToolbarLabel(label string) widget.ToolbarItem {
	l := widget.NewLabelWithStyle(label, fyne.TextAlignCenter ,fyne.TextStyle{Bold: true})
	l.MinSize()
	return &toolbarLabel{l}
}

func (t *toolbarLabel) ToolbarObject() fyne.CanvasObject {
	return t.Label
}

2. Compare the height of the buttons between the two toolbars. This can also be replicated if a Label is inside the HBox (acts the same as in Toolbar).

func MainScreen() fyne.CanvasObject {
	
	// Menu
	toolbar_hbox := container.NewHBox(
		widget.NewToolbarAction(theme.FolderIcon(), func() {
			fmt.Println("profile settings clicked in toolbar")
		}).ToolbarObject(),

		widget.NewToolbarSpacer().ToolbarObject(),
		widget.NewToolbarAction(theme.FolderIcon(), func() {
			fmt.Println("log out clicked in toolbar")
		}).ToolbarObject(),
	)

	toolbar_tb := widget.NewToolbar(
		widget.NewToolbarAction(theme.FolderIcon(), func() {
			fmt.Println("profile settings clicked in toolbar")
		}),
		element.NewToolbarLabel("marmiha"),
		widget.NewToolbarSpacer(),
		widget.NewToolbarAction(theme.FolderIcon(), func() {
			fmt.Println("log out clicked in toolbar")
		}),
	)


	return container.NewBorder(toolbar_tb, toolbar_hbox, nil, nil)
}

Screenshots:

Device (please complete the following information):

• OS: Windows
• Version: 10
• Go version: go 1.16.3 windows/amd64
• Fyne version: v2.0.3

[andydotxyz]

I think we may have broken this with the 2.0 changes to how widgets are padded.

[andydotxyz]

Fix is on develop branch now, will be in 2.1 release.