BUG, MAINT: Catch non 200 codes

[ganesh-k13]

Changes

Honestly one thing lead to another and here is what I ended up doing:

1. Fix the actual problem, i.e., catch non-200 responses and handle them: 1.1. In the case of a 422, raise a TypeError (same as before), but without all the extra processing. Now I'm pretty sure (take this with a pinch of salt :)) the status code check is sufficient, we need not check the json for type error 1.2. In case of every other error, raise an HTTPError with a meaningful error message
2. Add test cases for the new if and some more test cases for the TypeError
3. There was a lot of repeated code, so I added a few extensible fixtures, so will be easy to make changes, but reduces code at the same time

Example:

from vetiver.server import predict
from vetiver.data import mtcars

endpoint = "http://127.0.0.1:8080/predict1"  # Notice incorrect URL

# res = predict(endpoint, data={1:2, 2:3})
res = predict(endpoint, data=mtcars)

print(res)

Before:

Traceback (most recent call last):
  File "/home/ganesh/os/tmp/pred.py", line 7, in <module>
    res = predict(endpoint, data=mtcars)
  File "/home/ganesh/.local/lib/python3.10/site-packages/vetiver/server.py", line 265, in predict
    response_df = pd.DataFrame.from_dict(response.json())
  File "/home/ganesh/.local/lib/python3.10/site-packages/pandas/core/frame.py", line 1762, in from_dict
    return cls(data, index=index, columns=columns, dtype=dtype)
  File "/home/ganesh/.local/lib/python3.10/site-packages/pandas/core/frame.py", line 662, in __init__
    mgr = dict_to_mgr(data, index, columns, dtype=dtype, copy=copy, typ=manager)
  File "/home/ganesh/.local/lib/python3.10/site-packages/pandas/core/internals/construction.py", line 493, in dict_to_mgr
    return arrays_to_mgr(arrays, columns, index, dtype=dtype, typ=typ, consolidate=copy)
  File "/home/ganesh/.local/lib/python3.10/site-packages/pandas/core/internals/construction.py", line 118, in arrays_to_mgr
    index = _extract_index(arrays)
  File "/home/ganesh/.local/lib/python3.10/site-packages/pandas/core/internals/construction.py", line 656, in _extract_index
    raise ValueError("If using all scalar values, you must pass an index")
ValueError: If using all scalar values, you must pass an index

Now:

Traceback (most recent call last):
  File "/home/ganesh/os/mlops/vetiver-python/pred.py", line 7, in <module>
    res = predict(endpoint, data=mtcars)
  File "/home/ganesh/os/mlops/vetiver-python/vetiver/server.py", line 270, in predict
    raise requests.exceptions.HTTPError(
requests.exceptions.HTTPError: Could not obtain data from endpoint with error: 404 Client Error: Not Found for url: http://127.0.0.1:8080/predict1

resolves: #71

PS: Totally fine with getting rid of the extra stuff and just fixing the error, 81818dd2e004ad55fc8ac30a4774303a698eb1ef does that.

[isabelizimm]

This looks great! I updated the statsmodels and xgboost frameworks to pass tests + match test_predict.