Move sql preprocessors to exasol_data_science_utils_python.preprocessing.sql
Move scikit-learn transformers to exasol_data_science_utils_python.preprocessing.scikit_learn
Extended MockSQLExecutor and MockResultSet
Rename sql.TablePreprocessor and related files to SQLTablePreprocessor
Add ColumnDescriptionBasedTablePreprocessorFactory and all necessary classes
Add tests for ScikitLearnTransformers
Add SKLearnPrefittedColumnTransformer
Introduce ColumnSetPreprocessor as members of TablePreprocessor
SKLearnPrefittedOneHotTransformer changed to, not use the contrast matrix, to transform data. Instead we use the algorithm to create the contrast matrix on the fly on the input data. This saves memory by not storing the contrast matrix, but it might be a bit slower. However, memory is more important, because this limits the number of parallel instances.
Changed Model Iterators and UDFs to use TablePreprocessors and Factories
Closes #21