Add trait ComponentConstructor

## What problem does this solve or what need does it fill?

For rapier and avian, Collider is not implemented with `Reflect`. We cannot use extra properties in GLFT to reflect to create components.

Can we add a ComponentConstructor or something else to create a component from a reflectable constructor.

## What solution would you like?

Allow Component convert from another reflectable type
```rust
#[derive(Component)]
struct Foo {
....
}

impl Foo {
pub fn new_a (...) { ... }
pub fn new_b (...) { ... }
}

#[derive(Reflect, ComponentConstructor)]
enum FooConstructor {
A( ... ),
B( ... ),
}

impl ComponentConstructor for FooConstructor {
type C = Foo;
pub fn to_component(self) -> C {
....
}
}

....

// for spawn

commands.spawn(( FooConstructor::A( .... ), ))
// should same with
commands.spawn(( Foo::new_a( ... ), ))

```

## What alternative(s) have you considered?

For avian, they use https://github.com/Jondolf/avian/blob/39a7480cd1915bc5266aa8ebd3c3436d4d0568b0/src/collision/collider/backend.rs#L358C4-L358C30 to convert Constructor to Component.