potential raw_unicode_escape error when debugging customized BINARY field 
Did you not read the [code comment](https://github.com/coleifer/peewee/blob/master/peewee.py#L658-L661)? This is not part of the public API. > Did you not read the code comment? This is not part of the public API.

Hi coleifer, I am using `logger.debug("sql is %s", query)` with one of the parameter as a customized mysql BINARY field. I think it fits the code comment of  "This function is intended for debugging or logging purposes ONLY".

Unless there's another way to debug the SQL I am unaware of?
 The correct way to do this is:

```python

query = MyModel.select().where(MyModel.foo == 'bar')
sql, params = query.sql()
```

You can inspect the sql string, which contains proper placeholders for the parameters, and the parameters themselves.
Hi,

I created a BINARY field following the doc

https://docs.peewee-orm.com/en/latest/peewee/models.html#creating-a-custom-field

When debugging the SQL, peewee will try `utf8` or `raw_unicode_escape` the `bytes()` parameter, at one time my bytes happens to be `b"\x0ee\xd4\xee\xff\xc0\x02r\xc2\\U0'\x00"`, which will error in [_query_val_transform](https://github.com/coleifer/peewee/blob/master/peewee.py#L683)

```
UnicodeDecodeError
'rawunicodeescape' codec can't decode bytes in position 9-11: truncated \UXXXXXXXX escape
```

I think it's because we assume the in SQL parameter, `bytes()` are displayable strings but unfortunately it will fail when there's an illegal "\U" literal inside the string.