Add Clone derive to Room struct

[jowillianto]

I have no idea why, but somehow Clone is not derived for livekit::Room. In general, livekit::Room contains only an Arc, and by default this should safely implement Clone without any issue. If the design is to only let livekit::Room own RoomInner, perhaps using a Box is the better way.

[CLAassistant]

All committers have signed the CLA.

[ladvoc]

Good points! I will take a look at the internals and determine what the implications of cloning here are.

[1egoman]

@jowillianto Just to understand the context of the change a bit better, can you give a quick summary of your use case that requires cloning a room?

[jowillianto]

Hi! I am trying to pass room around to send messages from multiple threads.

[jowillianto]

I found a case it would make sense for Room to not implement Clone, however, this case does not apply to this repo. Here is the summary of the case:

struct B {
  // some data
}

// writer to structure B
// should not clone or double destruct. 
struct A {
  inner: Arc<B>
}
impl Drop for A {
  fn drop(&mut self) {
    self.inner.cancel(); // cancel somethind in B. 
  }
}

// reader to structure B
#[derive(Clone)]
struct C {
  inner: Arc<B>
}

I looked for if such Drop behaviour is implemented for RoomSession or Room, but since it is not, I think I can assume that it is safe.