### Godot version

4.0.2.stable.official.7a0977ce2

### System information

Linux

### Issue description

The following code fails with godot-cpp
```c++
Variant variant_int = 1234;
double double_value = variant_int;
UtilityFunctions::print(double_value); // prints 0. it must be 1234

Variant double_variant = 6789.0;
int int_value = double_variant;
UtilityFunctions::print(int_value); // prints 0. it must be 1234

Variant variant_string = "12345";
StringName string_name = variant_string;
UtilityFunctions::print(string_name); // Segmentation Fault!
```

When godot-cpp converts a `Variant` to another type, it calls `type_from_variant_constructor` without checking its type. It only does  `reinterpret_cast` and does no type conversion.
I think this issue can be solved by implementing type conversion on the godot-cpp side or by making `type_from_variant_constructor` do the type conversion.

### Steps to reproduce

Unzip the minimal reproduction project and run `scons` to build the GDExtension.

### Minimal reproduction project

[variant-conversion-issue.zip](https://github.com/godotengine/godot/files/11171860/variant-conversion-issue.zip)

case Variant::COLOR:
				init_color(v);
				break;
			case Variant::STRING_NAME:
				init_string_name(v);
				break;
			case Variant::NODE_PATH:
				init_node_path(v);
				break;
			case Variant::CALLABLE:
				init_callable(v);
				break;
			case Variant::SIGNAL:
				init_signal(v);
				break;
			case Variant::DICTIONARY:
				init_dictionary(v);
				break;
			case Variant::ARRAY:
				init_array(v);
				break;
			case Variant::PACKED_BYTE_ARRAY:
				init_byte_array(v);
				break;
			case Variant::PACKED_INT32_ARRAY:
				init_int32_array(v);
				break;
			case Variant::PACKED_INT64_ARRAY:
				init_int64_array(v);
				break;