Livemap: Add zooming-in for geom_text()/geom_label()

[INekrasova-HORIS]

Livemap: Add zooming-in for geom_text()/geom_label()

Now we have parameters data_size_zoomin and const_size_zoomin for geom_livemap() which control how zooming-in of the map widget increases size of geometry objects (circles, lines etc.) on map. We need to add such opportunity for text on the map.