Formula related bug fixes and improvements
Created by: jassak
Changelog:
- Implement filter parser for
query_from_formula
- Update Logistic Regression to accept filters
- Update PCA and Pearson to accept filters
- Fix Extreme bug: escaping quotes
- Remove formula from Pearson
- Bug fix in Logistic (proper error message when one category is passed)
- Bug fix in PCA: duplicate header in tabular-data