Improve styles menu layer

[Damianofds]

• The indentation of the layers names must be improved: the layer names should be placed always at the left-most border and indented just in presence of subgroups. the presence or absence of icons (info, legend or timeseries menu icons ) must be correct handled
• when a layergroup is selected and expanded the header and outline becames orange like the info button so If an infobutton is present on the header of layergroups disappears when the layergroup is expanded.