When migrating a table with a `binary` key in `-verbose` mode, different
sequences of bytes may prevent execution output from being logged, or
correctly logged, to the console.

This happens because the `MigrationRange*Values` are printed to the
screen without any type of encoding. One particularly problematic
sequence is `0x27`, `Escape`, which causes the terminal to stop logging
for the duration of the migration:

```
2025-05-23 11:53:27 INFO Listening on unix socket file: /tmp/gh-ost.test.binfoo.sock
2025-05-23 11:53:27 INFO Intercepted changelog state ReadMigrationRangeValues
2025-05-23 11:53:27 INFO Handled changelog state ReadMigrationRangeValues
2025-05-23 11:53:27 INFO Migration min values: [
```

This commit changes the to-string rendering for `binary` keys, rendering
the values as a hex string rather than an unescaped series of bytes.