Add option to check if hotkey is released

This was already possible previously by inverting the logic with a
"not", however, this should it make it more obvious that this type of
check is possible.

plugins/base/utils/hotkey-helpers.cpp

@@ -116,6 +116,9 @@ void Hotkey::Callback(void *data, obs_hotkey_id, obs_hotkey_t *, bool pressed)
 	if (pressed) {
 		hotkey->_lastPressed =
 			std::chrono::high_resolution_clock::now();
+	} else {
+		hotkey->_lastReleased =
+			std::chrono::high_resolution_clock::now();
 	}
 	hotkey->_pressed = pressed;
 }

plugins/base/utils/hotkey-helpers.hpp

@@ -27,6 +27,7 @@ public:
 
 	bool GetPressed() const { return _pressed; }
 	auto GetLastPressed() const { return _lastPressed; }
+	auto GetLastReleased() const { return _lastReleased; }
 	std::string GetDescription() const { return _description; }
 	bool UpdateDescription(const std::string &);
 
@@ -43,6 +44,7 @@ private:
 	obs_hotkey_id _hotkeyID = OBS_INVALID_HOTKEY_ID;
 	bool _pressed = false;
 	std::chrono::high_resolution_clock::time_point _lastPressed{};
+	std::chrono::high_resolution_clock::time_point _lastReleased{};
 	// When set will not attempt to share settings with existing hotkey
 	bool _ignoreExistingHotkeys = false;
 };