### Godot version

4.0beta12

### System information

all

### Issue description

In `extension_api.json` we have some function that uses parameter typed after a global enum and display it as a bitfield:
```js
{
	"name": "set_button_mask",
	"is_const": false,
	"is_vararg": false,
	"is_static": false,
	"is_virtual": false,
	"hash": 3950145251,
	"arguments": [
		{
			"name": "mask",
			"type": "bitfield::MouseButtonMask" // bitfield prefix here !
		}
	]
},
```

However the global enum's own definition doesn't mention it is a bitfield:
```js
{
	"name": "MouseButtonMask",
	// No "bitfield" field here !
	"values": [
		{
			"name": "MOUSE_BUTTON_MASK_LEFT",
			"value": 1
		},
		{
			"name": "MOUSE_BUTTON_MASK_RIGHT",
			"value": 2
		},
		{
			"name": "MOUSE_BUTTON_MASK_MIDDLE",
			"value": 4
		},
		{
			"name": "MOUSE_BUTTON_MASK_MB_XBUTTON1",
			"value": 128
		},
		{
			"name": "MOUSE_BUTTON_MASK_MB_XBUTTON2",
			"value": 256
		}
	]
},
```

On the other hand, the non-global enums (i.e. the ones defined as part of a class) have this `is_bitfield` field.
So I guess we should add it to global enum too.

### Steps to reproduce

n/a

### Minimal reproduction project

n/a
}
							if (i == -1) {
								d2["return_value"] = d3;
							} else {
								arguments.push_back(d3);
							}
						}
						if (arguments.size()) {
							d2["arguments"] = arguments;
						}
						methods.push_back(d2);
					}
				}
				if (methods.size()) {
					d["methods"] = methods;
				}
			}
			{
				
				Array signals;
				List<MethodInfo> signal_list;
				ClassDB::get_signal_list(class_name, &signal_list, true);
				for (const MethodInfo &F : signal_list) {
					StringName signal_name = F.name;
					Dictionary d2;
					d2["name"] = String(signal_name);
					Array arguments;
					for (int i = 0; i < F.arguments.size(); i++) {
						Dictionary d3;
						d3["name"] = F.arguments[i].name;