Task names require harmonization

We should create a single task sanitization step before generating any features which harmonize/handle known issues:

- Merge known inconsistencies
```
Animal-Fluency/Animal-fluency
Picture-Description/ Picture-description
  Prolonged-Vowel/  Prolonged-vowel
  Rainbow-Passage/  RainbowPassage
  Story-Recall/  Story-recall
```
- merge v2 in
- remove "-task" as it is a keyword
- remove underscores