overlay: categorize lights for different cab types (#576)

## Link to GitHub Issue or related Pull Request, if one exists
#574 

## Description of change
Refactor so that grouping of lights are in common I/O code. Add this to
IIDX/SDVX/DDR/GitaDora.

## Testing

src/spice2x/cfg/light.h

@@ -11,6 +11,7 @@ class Light {
 private:
     std::vector<Light> alternatives;
     std::string lightName;
+    std::string lightCategory;
     std::string deviceIdentifier = "";
     unsigned int index = 0;
     bool is_temporary = false;
@@ -23,6 +24,8 @@ public:
     float override_state = 0.f;
 
     explicit Light(std::string lightName) : lightName(std::move(lightName)) {};
+    explicit Light(std::string lightName, std::string lightCategory) :
+        lightName(std::move(lightName)), lightCategory(std::move(lightCategory)) {};
 
     std::string getDisplayString(rawinput::RawInputManager* manager);
 
@@ -51,6 +54,14 @@ public:
         return this->lightName;
     }
 
+    inline const std::string &getCategory() const {
+        return this->lightCategory;
+    }
+
+    inline void setCategory(std::string category) {
+        this->lightCategory = std::move(category);
+    }
+
     inline const std::string &getDeviceIdentifier() const {
         return this->deviceIdentifier;
     }