overlay: "reset all" buttons for buttons/overlay/analog tabs (#578)

## Link to GitHub Issue or related Pull Request, if one exists
#576 

## Description of change
Add `Reset All` buttons to these tabs which clears out bindings to none
/ default.

For keypads, introduce a special `Use Preset` button which lets users
pick between numpad and top row number keys.

Update UI-visible string used for vKeys, especially the numpad ones
(e.g., `.` is now `Numpad .` to distinguish from the regular `.`
period).

Breaking change: if the user never had `P1 Keypad 00` set, the default
will change from `Enter` to `Numpad -` since both enter keys trigger the
same. This will affect a small number of popn/ddr players. They can just
change it back.

## Testing
*how was the code tested?*

src/spice2x/cfg/api.cpp

@@ -37,7 +37,11 @@ std::vector<Button> GameAPI::Buttons::sortButtons(
         for (auto &bt : buttons) {
             if (name == bt.getName()) {
                 button_found = true;
-                sorted.push_back(bt);
+                Button button_new = bt;
+                if (vkey_defaults) {
+                    button_new.setVKeyDefault(vkey_defaults->at(index));
+                }
+                sorted.push_back(button_new);
                 break;
             }
         }
@@ -47,6 +51,7 @@ std::vector<Button> GameAPI::Buttons::sortButtons(
 
             if (vkey_defaults) {
                 button.setVKey(vkey_defaults->at(index));
+                button.setVKeyDefault(vkey_defaults->at(index));
             }
         }
 

src/spice2x/cfg/button.cpp

@@ -44,7 +44,7 @@ std::string Button::getVKeyString() {
         case 0x0C:
             return "Clear";
         case 0x0D:
-            return "Enter";
+            return "Enter/Return";
         case 0x10:
             return "Shift";
         case 0x11:
@@ -183,37 +183,37 @@ std::string Button::getVKeyString() {
         case 0x5D:
             return "Apps";
         case 0x60:
-            return "Num 0";
+            return "Numpad 0";
         case 0x61:
-            return "Num 1";
+            return "Numpad 1";
         case 0x62:
-            return "Num 2";
+            return "Numpad 2";
         case 0x63:
-            return "Num 3";
+            return "Numpad 3";
         case 0x64:
-            return "Num 4";
+            return "Numpad 4";
         case 0x65:
-            return "Num 5";
+            return "Numpad 5";
         case 0x66:
-            return "Num 6";
+            return "Numpad 6";
         case 0x67:
-            return "Num 7";
+            return "Numpad 7";
         case 0x68:
-            return "Num 8";
+            return "Numpad 8";
         case 0x69:
-            return "Num 9";
+            return "Numpad 9";
         case 0x6A:
-            return "*";
+            return "Numpad *";
         case 0x6B:
-            return "+";
+            return "Numpad +";
         case 0x6C:
-            return "Seperator";
+            return "Numpad Seperator";
         case 0x6D:
-            return "-";
+            return "Numpad -";
         case 0x6E:
-            return ".";
+            return "Numpad .";
         case 0x6F:
-            return "/";
+            return "Numpad /";
         case 0x70:
             return "F1";
         case 0x71:

src/spice2x/cfg/button.h

@@ -49,6 +49,10 @@ private:
     std::string name;
     std::string device_identifier = "";
     unsigned short vKey = INVALID_VKEY;
+
+    // default bindings are always naive
+    unsigned short vKey_default = INVALID_VKEY;
+
     ButtonAnalogType analog_type = BAT_NONE;
     double debounce_up = 0.0;
     double debounce_down = 0.0;
@@ -125,6 +129,14 @@ public:
         this->vKey = vKey;
     }
 
+    inline unsigned short getVKeyDefault() const {
+        return this->vKey_default;
+    }
+
+    inline void setVKeyDefault(unsigned short vKey_default) {
+        this->vKey_default = vKey_default;
+    }
+
     inline ButtonAnalogType getAnalogType() const {
         return this->analog_type;
     }