### 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)

VariantTypeChanger<typename GetSimpleTypeT<T>::type_t>::change(r_ret);
	}
};
template <>
struct VariantTypeAdjust<Variant> {
	_FORCE_INLINE_ static void adjust(Variant *r_ret) {
		
	}
};
template <>
struct VariantTypeAdjust<Object *> {
	_FORCE_INLINE_ static void adjust(Variant *r_ret) {
		VariantInternal::clear(r_ret);
		*r_ret = (Object *)nullptr;
	}
};
template <class T>
struct VariantTypeConstructor {
	_FORCE_INLINE_ static void variant_from_type(void *r_variant, void *p_value) {
		
		memnew_placement(r_variant, Variant(*((T *)p_value)));
	}
	_FORCE_INLINE_ static void type_from_variant(void *r_value, void *p_variant) {
		
		memnew_placement(r_value, T(VariantInternalAccessor<T>::get(reinterpret_cast<Variant *>(p_variant))));
	}
};
#endif