Reformat everything with black (#737)

The biggest change is going from two-space indent to four. Black won't
ever do two. Since `kagglehub` uses Black, this makes us a bit more
stylistically consistent.

To use with Rider, you'd change some Settings:
> Editor > Code Style > Hard wrap = 120
> Tools > Black > Use Black = On save
> (May need to install Black in the local interpreter)

The line length was chosen to be consistent with `kagglehub`, and is
defined in `pyproject.toml`. Command:
```bash
black .
```
So both `kaggle` and `kagglesdk` are reformatted.

Updating dependency installation will be done in another PR.

Author: stevemessick

integration_tests/test_models.py

@@ -9,6 +9,7 @@
 
 # TODO(messick) Add a test that creates a dataset w/o specifying privacy that is created private.
 
+
 class TestModels(unittest.TestCase):
     def setUp(self):
         self.api = KaggleApi()