Add push button support for OFX plugins

This commit adds support for push buttons in OFX plugins by:

- Adding `kPushButton` to `NodeValue` enum
- Implementing `pushButtonClicked` slot in `PluginNode`
- Creating `NodeParamButton` widget for UI representation
- Updating `paraminstance.h` to handle push button instances
- Modifying `nodeparamviewwidgetbridge.cpp` to connect push button signals

app/widget/nodeparamview/nodeparamviewwidgetbridge.cpp

@@ -26,6 +26,7 @@
 
 #include "common/qtutils.h"
 #include "core.h"
+#include "nodeparambutton.h"
 #include "node/group/group.h"
 #include "node/node.h"
 #include "node/nodeundo.h"
@@ -40,6 +41,8 @@
 #include "widget/slider/integerslider.h"
 #include "widget/slider/rationalslider.h"
 
+#include <OpenImageIO/detail/fmt/base.h>
+
 namespace olive
 {
 
@@ -179,6 +182,13 @@ void NodeParamViewWidgetBridge::CreateWidgets()
 					&NodeParamViewWidgetBridge::WidgetCallback);
 			break;
 		}
+		case NodeValue::kPushButton: {
+			NodeInput input=GetInnerInput();
+			NodeParamButton *button=new NodeParamButton(input.name(),parent);
+			widgets_.append(button);
+			plugin::PluginNode* plugin_node=dynamic_cast<plugin::PluginNode*>(input.node());
+			connect(button, &NodeParamButton::onPressed, plugin_node, &plugin::PluginNode::pushButtonClicked);
+		}
 		}
 
 		// Check all properties