Validate that the columns passed to the a constraint exist in the data

[fealho]

We don't validate that the constraint is passed only existing columns, which may crash with mysterious error messages. Below is such an example:

import sdv
from sdv.constraints import Unique, OneHotEncoding
import pandas as pd
import numpy as np
from sdv.tabular import GaussianCopula

data = pd.DataFrame({
    'a': [1, 0],
    'b': [0, 1],
})

cnt = OneHotEncoding(['a','b','c'])
model = GaussianCopula(constraints=[cnt])
model.fit(data)
model.sample(10)

which produces the following traceback

Input In [10], in <cell line: 12>()
     10 cnt = OneHotEncoding(['a','b','c'])
     11 model = GaussianCopula(constraints=[cnt])
---> 12 model.fit(data)
     13 model.sample(10)

File ~/Desktop/SDV/sdv/tabular/base.py:147, in BaseTabularModel.fit(self, data)
    144 LOGGER.debug('Fitting %s to table %s; shape: %s', self.__class__.__name__,
    145              self._metadata.name, data.shape)
    146 if not self._metadata_fitted:
--> 147     self._metadata.fit(data)
    149 self._num_rows = len(data)
    151 LOGGER.debug('Transforming table %s; shape: %s', self._metadata.name, data.shape)

File ~/Desktop/SDV/sdv/metadata/table.py:588, in Table.fit(self, data)
    585 data = self._anonymize(data)
    587 LOGGER.info('Fitting constraints for table %s', self.name)
--> 588 constrained = self._fit_transform_constraints(data)
    589 extra_columns = set(constrained.columns) - set(data.columns)
    591 LOGGER.info('Fitting HyperTransformer for table %s', self.name)

File ~/Desktop/SDV/sdv/metadata/table.py:447, in Table._fit_transform_constraints(self, data)
    445 def _fit_transform_constraints(self, data):
    446     for constraint in self._constraints:
--> 447         data = constraint.fit_transform(data)
    449     return data

File ~/Desktop/SDV/sdv/constraints/base.py:294, in Constraint.fit_transform(self, table_data)
    283 def fit_transform(self, table_data):
    284     """Fit this Constraint to the data and then transform it.
    285 
    286     Args:
   (...)
    292             Transformed data.
    293     """
--> 294     self.fit(table_data)
    295     return self.transform(table_data)

File ~/Desktop/SDV/sdv/constraints/base.py:152, in Constraint.fit(self, table_data)
    149 self._fit(table_data)
    151 if self.fit_columns_model and len(self.constraint_columns) > 1:
--> 152     data_to_model = table_data[list(self.constraint_columns)]
    153     self._hyper_transformer = HyperTransformer(default_data_type_transformers={
    154         'categorical': 'OneHotEncodingTransformer',
    155     })
    156     transformed_data = self._hyper_transformer.fit_transform(data_to_model)

File ~/opt/anaconda3/envs/sdv/lib/python3.9/site-packages/pandas/core/frame.py:3511, in DataFrame.__getitem__(self, key)
   3509     if is_iterator(key):
   3510         key = list(key)
-> 3511     indexer = self.columns._get_indexer_strict(key, "columns")[1]
   3513 # take() does not accept boolean indexers
   3514 if getattr(indexer, "dtype", None) == bool:

File ~/opt/anaconda3/envs/sdv/lib/python3.9/site-packages/pandas/core/indexes/base.py:5782, in Index._get_indexer_strict(self, key, axis_name)
   5779 else:
   5780     keyarr, indexer, new_indexer = self._reindex_non_unique(keyarr)
-> 5782 self._raise_if_missing(keyarr, indexer, axis_name)
   5784 keyarr = self.take(indexer)
   5785 if isinstance(key, Index):
   5786     # GH 42790 - Preserve name from an Index

File ~/opt/anaconda3/envs/sdv/lib/python3.9/site-packages/pandas/core/indexes/base.py:5845, in Index._raise_if_missing(self, key, indexer, axis_name)
   5842     raise KeyError(f"None of [{key}] are in the [{axis_name}]")
   5844 not_found = list(ensure_index(key)[missing_mask.nonzero()[0]].unique())
-> 5845 raise KeyError(f"{not_found} not in index")

KeyError: "['c'] not in index"