Rusty Russell b5d1acee45 wire: call unknown types "UNKNOWN X" not "INVALID X". ...

It's freaking people out when they see things like:

```
 2024-11-11T05:26:41.281Z DEBUG ...53c-connectd: peer_out INVALID 22859
```

Fixes: https://github.com/ElementsProject/lightning/issues/7802
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Changelog-Changed: connectd: log unknown messages as "UNKNOWN" not "INVALID" to avoid freaking people out.

2024-12-02 15:09:45 +10:30

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