Support zc_reply_fifo_new_unbounded

[YuanYuYuan]

Describe the feature

A handler to an unbounded flume channel was supported in 0.11.0 but missing in 1.0.0.

[DenisBiryukov91]

In 0.11.0 unbounded channel was created by passing a 0 channel size, now passing 0 creates a rendezvous channel. I believe Zenoh rust also does not support unbounded flume-channel as its predefined handler. It was discussed with @Mallets and agreed that it does not worth implementing unbounded channel in zenoh-c.

[YuanYuYuan]

I see. Then let's close this issue 😁.

[wyfo]

Unbounded is rarely a good idea. A lot of channels uses the same implementation for both bounded and unbounded, so there is no difference in memory use. flume is just a mutex around a VecDeque (I'm quite disappointed to discover that), so keeping it bounded to avoid overflowing the memory is always better, and passing usize::MAX has pretty much the same effect than as an unbounded one.