Consolidating state files

### What is the problem you're trying to solve

We currently have:

StateDir:
```
ls -lA ~/.local/share/nerdctl/1935db59/containers/default/431f831244a436778b81cfd332e5f9395707b9f63ae9b02ca5307cb2b4c8fa31/
total 208
-rw------- 1 dmp dmp 185103 Dec 2 20:06 431f831244a436778b81cfd332e5f9395707b9f63ae9b02ca5307cb2b4c8fa31-json.log
-rw------- 1 dmp dmp 258 Dec 2 16:02 431f831244a436778b81cfd332e5f9395707b9f63ae9b02ca5307cb2b4c8fa31-json.log.1
-rw-r--r-- 1 dmp dmp 3 Dec 2 12:59 hostname
-rw------- 1 dmp dmp 73 Dec 2 12:59 lifecycle.json
-rw------- 1 dmp dmp 66 Dec 2 12:59 log-config.json
-rw-rw-r-- 1 dmp dmp 0 Dec 2 12:59 oci-hook.createRuntime.log
-rw-rw-r-- 1 dmp dmp 0 Dec 2 12:59 oci-hook.postStop.log
-rw-r--r-- 1 dmp dmp 43 Dec 2 12:59 resolv.conf
```

And separately, EtcHosts:
```
ls -lA ~/.local/share/nerdctl/1935db59/etchosts/default/431f831244a436778b81cfd332e5f9395707b9f63ae9b02ca5307cb2b4c8fa31/
total 8
-rw-r--r-- 1 dmp dmp 260 Dec 2 16:02 hosts
-rw-r--r-- 1 dmp dmp 465 Dec 2 12:59 meta.json
```

I do not know if there was a reason for keeping these separate?

From a glance, it looks like etchosts is unnecessary and could be folded inside the container statedir.

Thoughts?

### Describe the solution you'd like

Merge.

### Additional context

_No response_