rb: touch debug overlay, tweak scaling (#801)

## Link to GitHub Issue or related Pull Request, if one exists
n/a

## Description of change
Similar to #797, draw an overlay to debug touch issues for reflec beat.

For rb, we draw on the ImGui surface. Draw horizontal and vertical line
for triggered sensors, and also a bounding box if scaling is in use.

Make small tweaks to how scaling works.

## Testing
Verified volzza 2 / reflesia / 1st game (landscape KBR)

src/spice2x/launcher/options.cpp

@@ -2739,6 +2739,18 @@ static const std::vector<OptionDefinition> OPTION_DEFINITIONS = {
         .category = "Game Options",
         .quick_setting_category = "Game",
     },
+    {
+        // RBTouchDebug
+        .title = "RB Touch Debug Overlay",
+        .name = "rbtouchdebug",
+        .desc = "Draw lines to show IR sensor emulation state.\n\n"
+            "Note: lines will not perfectly align with touches; this is by design, it's showing the "
+            "IR sensor state, before the game applies its own touch detection algorithm.",
+        .type = OptionType::Bool,
+        .game_name = "Reflec Beat",
+        .category = "Game Options",
+        .quick_setting_category = "Game",
+    },
     {
         // spice2x_RBTouchScale
         .title = "RB Touch Emulation Scale",