Reflectors watch: close after stop

[manics]

I'm trying to track down the

Unclosed client session
client_session: <aiohttp.client.ClientSession object at 0x7fcfe6bbc690>

warning in lsc-sde/lsc-sde#93 (comment)

I don't know if this is the cause, but based on the context manager code in
https://github.com/tomplus/kubernetes_asyncio/blob/v21.7.1/kubernetes_asyncio/watch/watch.py#L212-L216
we should call close() anyway.

[consideRatio]

I think this is correct and suitable to do, but I struggle to become confident about it.

Do you want to merge or ask for another set of eyes?

[consideRatio]

By awaiting close, we'll have a delay of finalizing the _watch_and_update function call.

The _watch_and_update is called via self.watch_task = asyncio.create_task(self._watch_and_update()), and then self.watch_task is checked to be .done() or not at several locations.

The thing I'm not getting confident about, is the consequences of now waitinging for that to finalize. I figure at worst we get a performance hit, but I think we'll end up with something more robust. Due to that, I'm leaning towards we go for a merge.

[manics]

Thanks for reviewing, let's merge then!

I want to look into #858 , maybe we can have a beta-3 after that

[consideRatio]

Thank you for working this @manics!!