BUG: Fix exceptions when Series.interpolate's `order` parameter is missing or invalid
closes #24014
xref #10633
- [x] tests added / passed
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry

Before this change, when the `Series.interpolate()` method was called with invalid arguments,  exceptions with informative messages would be raised internally, but then caught and suppressed.  An exception with a potentially misleading message would be raised instead.

For example, when interpolate is called with `method='spline'`, an `order` argument must also be supplied.  This is checked internally, but when the `order` argument was missing, a confusing error would be raised:
```
>>> import pandas as pd
>>> s = pd.Series([0, 1, pd.np.nan, 3, 4])
>>> s.interpolate(method='spline')
Traceback (most recent call last):
...
ValueError: invalid method 'spline' to interpolate.
```

This problem was reported as issues #10633 and #24014.

After this change, a specific and correct exception (previously caught and discarded internally) is raised:
```
>>> import pandas as pd
>>> s = pd.Series([0, 1, pd.np.nan, 3, 4])
>>> s.interpolate(method='spline')
...
ValueError: You must specify the order of the spline or polynomial.
```

In addition, light validation is now performed on the `order` parameter before it is passed to a `scipy` class.  Previously, `pandas` would check if `order` was truthy in the Python sense.  If `order` was non-zero and invalid, a scipy error would propagate to the user:
```
>>> s.interpolate(method='spline', order=-1)
Traceback (most recent call last):
...
dfitpack.error: (1<=k && k<=5) failed for 3rd argument k: fpcurf0:k=-1
```

After this change, a more understandable exception is raised in this case:
```
>>> s.interpolate(method='spline', order=-1)
Traceback (most recent call last):
...
ValueError: order needs to be specified and greater than 0
```