[Python] Missing byte_width attribute on most datatypes

### Describe the enhancement requested

This is a small annoyance:
```python
>>> pa.binary(11).bit_width
88
>>> pa.binary(11).byte_width
11
>>> pa.int64().bit_width
64
>>> pa.int64().byte_width
Traceback (most recent call last):
  Cell In[2], line 1
    pa.int64().byte_width
AttributeError: 'pyarrow.lib.DataType' object has no attribute 'byte_width'
```

### Component(s)

Python