Mutually exclusive CCI categories not considered

[sfortin1]

The current implementation of the CCI in the FeatureExtraction package does not account for mutually exclusive comorbid condition categories; e.g.:
• When both mild vs. moderate to severe liver disease are observed, only the weights for moderate to severe liver disease should be counted
• When both diabetes with vs. without complications are observed, only the weights for diabetes with complications should be counted
• When both ‘any malignancy’ and metastatic tumor are observed, only the weights for metastatic tumor should be counted