text: Title: [FEA] featurize/umap should allow specifying which columns to multilabel
  Body: **Is your feature request related to a problem? Please describe.**
  
  Right now multilabel is default-off and only works when there is only 1 column, and it is lists of lists
  
  
  **Describe the solution you'd like**
  
  It should really be either auto-detect of all columns or explicit opt-in to specific columns
  
  **Describe alternatives you've considered**
  
  `g.featurize(y=['dirty_categorical'], multilabel=[ 'list_of_list_col' ])`
  
  
  **Additional context**
  
  * common in recommendations
  * common in community detection
  * ...
  
  
  