Support `testcontainers/ryuk` as resource reaper about testcontainers-rs

[DDtKey]

In general, I like the idea to keep both.

But I guess we need to extend watchdog to allow registration of networks (and named volumes?) to make it enabled by default. For now it works only for containers.

Anyway, I think ryuk should be implemented under separate feature ryuk, so we can keep watchdog and extend separately

[mervyn-mccreight]

We could also think about keeping watchdog for those who can't use ryuk, because of some constraints (e.g. using podman in rootless mode), or even make it the default if ryuk is not enabled. Or just provide both it behind features and the users can choose by themselves whether they want to use ryuk or watchdog.

WDYT?