overlay: remove multiple pages from Buttons/Overlay/Lights tabs, replace with tree layout (#541)

The old pages UI was not intuitive and often led to questions like:

* How do I bind multiple controllers to a single input?? (failure to
discover)
* I have a ghost input that won't go away, how do I fix this? Is this a
bug? (non-intuitive UI - there are too many pages and finding out where
each binding is potentially requires scrolling through 100 pages)
* Potential perf issue - user binds too many by accident, or puts
bindings all the way in page 99, requiring us to walk each element in
the vector, wasting precious CPU cycles during an input poll.

This PR removes the multiple pages, and puts everything on a single
page, showing multiple binds in a tree structure.

It also puts a hard limit on how many alternate bindings can be made (8
for buttons, 16 for lights), though if the user has configured more in
older version they will be respected.

src/spice2x/cfg/button.h

@@ -45,6 +45,7 @@ private:
     double debounce_up = 0.0;
     double debounce_down = 0.0;
     bool invert = false;
+    bool is_temporary = false;
 
     GameAPI::Buttons::State last_state = GameAPI::Buttons::BUTTON_NOT_PRESSED;
     float last_velocity = 0.f;
@@ -164,6 +165,14 @@ public:
         this->last_velocity = last_velocity;
     }
 
+    inline bool isTemporary() const {
+        return this->is_temporary;
+    }
+
+    inline void setTemporary(bool is_temporary) {
+        this->is_temporary = is_temporary;
+    }
+
     inline unsigned short getVelocityThreshold() const {
         return this->velocity_threshold;
     }
@@ -172,6 +181,20 @@ public:
         this->velocity_threshold = velocity_threshold;
     }
 
+    inline bool isValid() {
+        // temporarily created by UI
+        if (isTemporary()) {
+            return true;
+        }
+
+        // nothing is set
+        if (getDeviceIdentifier().empty() && getVKey() == INVALID_VKEY) {
+            return false;
+        }
+
+        return true;
+    }
+
     void getMidiVKey(int& channel, int& index);
     void setMidiVKey(rawinput::RawInputManager* manager, bool is_note, int channel, int index);
 

src/spice2x/cfg/light.h

@@ -13,6 +13,7 @@ private:
     std::string lightName;
     std::string deviceIdentifier = "";
     unsigned int index = 0;
+    bool is_temporary = false;
 
 public:
     float last_state = 0.f;
@@ -65,4 +66,26 @@ public:
     inline void setIndex(unsigned int index) {
         this->index = index;
     }
+
+    inline bool isTemporary() const {
+        return this->is_temporary;
+    }
+
+    inline void setTemporary(bool is_temporary) {
+        this->is_temporary = is_temporary;
+    }
+
+    inline bool isValid() {
+        // temporarily created by UI
+        if (isTemporary()) {
+            return true;
+        }
+
+        // nothing is set
+        if (getDeviceIdentifier().empty()) {
+            return false;
+        }
+
+        return true;
+    }
 };