Plotting ExtensionArrays
- [x] closes #26173
- [ ] tests added / passed
- [ ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

How do I go about adding tests for that rely on an external module?
Would be something like
```python3
df = pd.DataFrame({
        "length" : pd.Series([1,2],dtype = pd.Int16Dtype),
        "width" : PA_([2,3], dtype="pint[m]"),
        "distance" : PA_([2,3], dtype="in"),
        "height" : PA_([2,3], dtype=ureg.m),
        "depth" : PA_.from_1darray_quantity(Q_([2,3],ureg.mm)),
    })
df.plot()
```