Improve viewer screenshots, add camera orientation option

• Added glow::viewer::camera_orientation viewer config object, taking in azimuth, altitude and optional distance to center
• Added custom resolution option to screenshot tool
• Background grid hidden in screenshots
• Added Info tab to viewer menu display camera info (same format as taken by camera_orientation)
• Added "Reset Camera" action to viewer menu, hotkey F3 (resets to position dictated by scene, compatible with interactive mode)

viewer/glow-extras/viewer/detail/command_queue.hh

@@ -2,8 +2,8 @@
 
 #include <functional>
 #include <memory>
-#include <vector>
 #include <variant>
+#include <vector>
 
 #include <glow-extras/viewer/Scene.hh>
 #include <glow-extras/viewer/layout.hh>
@@ -115,6 +115,18 @@ public:
         return res;
     }
 
+    static command sceneCameraOrientation(tg::angle azimuth, tg::angle altitude, float distance)
+    {
+        command res{instruction::ModifyScene};
+        res.data = [azimuth, altitude, distance](Scene& s) {
+            s.customCameraOrientation = true;
+            s.cameraAzimuth = azimuth;
+            s.cameraAltitude = altitude;
+            s.cameraDistance = distance;
+        };
+        return res;
+    }
+
     static command sceneClearAccum()
     {
         command res{instruction::ModifyScene};