CMake cleanup (#2489)

* CMake Cleanup
* Warning suppression with CEF
* Use SGCT tinyxml in skybrowser for now
* Disable warnings about missing field initializers

modules/globebrowsing/src/layermanager.cpp

@@ -145,7 +145,7 @@ std::array<LayerGroup*, LayerManager::NumLayerGroups> LayerManager::layerGroups(
     ZoneScoped
 
     std::array<LayerGroup*, NumLayerGroups> res = {};
-    for (int i = 0; i < NumLayerGroups; ++i) {
+    for (size_t i = 0; i < NumLayerGroups; ++i) {
         res[i] = _layerGroups[i].get();
     }
     return res;

modules/globebrowsing/src/renderableglobe.cpp

@@ -1713,7 +1713,7 @@ void RenderableGlobe::recompileShaders() {
     }
 
     ghoul::Dictionary layerGroupNames;
-    for (int i = 0; i < layers::Groups.size(); ++i) {
+    for (size_t i = 0; i < layers::Groups.size(); ++i) {
         layerGroupNames.setValue(
             std::to_string(i),
             std::string(layers::Groups[i].identifier)