Launcher improvements

Launcher windows are more Starter-like now:
- The scenery picker, vehicle list and keymapper buttons are now tied to the top portion of the screen.
- The current window is spanning the entire rest of the screen.
- Scenarios are now grouped into categories in the exact same way as Starter does.
- Some drawbacks include:
  - Currently you cannot edit the current trainset, as the vehicle picker window overwrites the scenario list window.
  - The GUI doesn't update when the screen resolution is changed.

widgets/cameraview_extcam.cpp

@@ -6,7 +6,7 @@
 #include "widgets/cameraview_extcam.h"
 #include "stb/stb_image.h"
 #include "Globals.h"
-#include "Logs.h"
+#include "translation.h"
 #include "extras/piped_proc.h"
 
 ui::cameraview_panel::cameraview_panel()

widgets/perfgraphs.cpp

@@ -1,12 +1,9 @@
 #include "stdafx.h"
 #include "widgets/perfgraphs.h"
 #include "Timer.h"
+#include "translation.h"
 
-perfgraph_panel::perfgraph_panel()
-    : ui_panel(STR("Performance"), false)
-{
-
-}
+perfgraph_panel::perfgraph_panel() : ui_panel(STR("Performance"), false) {}
 
 void perfgraph_panel::render_contents() {
 	if (ImGui::BeginCombo(STR_C("Timer"), timer_label[current_timer].c_str())) // The second parameter is the label previewed before opening the combo.