TD annotation: use more suitable properties

- see https://forum.freecadweb.org/viewtopic.php?f=35&t=40608 for details
- also simplify tooltips

src/Mod/TechDraw/App/DrawViewAnnotation.h

@@ -51,9 +51,9 @@ public:
     App::PropertyFont         Font;
     App::PropertyColor        TextColor;
     App::PropertyLength       TextSize;
-    App::PropertyInteger      LineSpace;
+    App::PropertyPercent      LineSpace;
     App::PropertyEnumeration  TextStyle; // Plain,Bold,Italic,Bold-Italic
-    App::PropertyFloat        MaxWidth;
+    App::PropertyLength       MaxWidth;
 
     virtual QRectF getRect() const;