Small debugging helper to keep track of alive providers

[Chralu]

Hi,

I just wrote the following ProviderObserver for my debugging needs : https://gist.github.com/Chralu/8a1ba5f49027ad10d96e91bc54db5780

It is probably perfectible, maybe useless, and surely not revolutionnary (you tell me 😅).
But I share it here in case it might help you... 😉

Any feedback welcome.