Make information part more consistent

[mdehoog]

From Richard Lane: (I have a catalogue from GeoModeller that has a summary of a "project" in an HTML page of information). There is some inconsistency in the presence/absence of "Information" and the activation of the blue Information button in the Layers and Catalogue panels. When I select an item in the Layers panel, the blue information icon lights up, and by selecting this, some information on the object (only its filename) is displayed in the "Information" tab below the 3D view. When I select the same item in the Catalogue panel, the Information icon doesn't light up. However, if I manually move to the Information tab (below the 3D view), there is information there to display - i.e., the HTML information that wasn't displayed in the Layers panel???