### 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
Dictionary api_dump;
	{
		
		Dictionary header;
		header["version_major"] = VERSION_MAJOR;
		header["version_minor"] = VERSION_MINOR;
#if VERSION_PATCH
		header["version_patch"] = VERSION_PATCH;
#else
		header["version_patch"] = 0;
#endif
		header["version_status"] = VERSION_STATUS;
		header["version_build"] = VERSION_BUILD;
		header["version_full_name"] = VERSION_FULL_NAME;
		api_dump["header"] = header;
	}
	const uint32_t vec3_elems = 3;
	const uint32_t vec4_elems = 4;
	const uint32_t ptrsize_32 = 4;
	const uint32_t ptrsize_64 = 8;
	static const char *build_config_name[4] = { "float_32", "float_64", "double_32", "double_64" };
	{
		
		constexpr struct {
			Variant::Type type;
			uint32_t size_32_bits_real_float;
			uint32_t size_64_bits_real_float;
			uint32_t size_32_bits_real_double;
			uint32_t size_64_bits_real_double;