Use clearer error message for unsupported encryption types (#1831)

Devices that announce an encryption type the library does not know, such
as `TPAP` used by newer Tapo devices (e.g. RV20 Max Plus), previously
failed with a generic message that dumped the whole encryption scheme:

```
Unsupported device 192.168.xx.xx of type SMART.TAPOROBOVAC with encrypt_scheme EncryptionScheme(is_support_https=True, encrypt_type='TPAP', http_port=4433, lv=2)
```

This can be rather confusing to interpret, as it does not tell what is
not supported (e.g., the device type is definitely supported on non-tpap
transports).
This PR adds a separate check and error message for cases where the
encryption type is not supported, giving this error:
```
Device 192.168.xx.xx (SMART.TAPOROBOVAC) uses unsupported encryption type TPAP
```

kasa/discover.py

@@ -845,6 +845,14 @@ class Discover:
                 discovery_result=discovery_result.to_dict(),
                 host=discovery_result.ip,
             )
+
+        if encrypt_type not in {e.value for e in DeviceEncryptionType}:
+            raise UnsupportedDeviceError(
+                f"Device {discovery_result.ip} ({type_}) uses unsupported "
+                f"encryption type {encrypt_type}",
+                discovery_result=discovery_result.to_dict(),
+                host=discovery_result.ip,
+            )
         return DeviceConnectionParameters.from_values(
             type_,
             encrypt_type,