Basic GUI client, login dialog, various comments fixes after copypaste.

client/internal/services/core/mainwindow/models/tab.go

@@ -0,0 +1,18 @@
+package models
+
+import (
+	"fyne.io/fyne/v2"
+	"fyne.io/fyne/v2/canvas"
+)
+
+// Tab is an internal representation of main window's tab that is responsible for showing content.
+type Tab struct {
+	// Name is a name for tab. Won't render by default on desktop, only on mouse hover, but will be rendered on mobiles.
+	Name string
+	// Widget is a widget shown in window.
+	Widget fyne.CanvasObject
+	// Icon is an icon to show on tab.
+	Icon canvas.Image
+	// BadgeCount is a number to show on tab, like unread messages, incompleted tasks, etc.
+	BadgeCount uint16
+}