Add standard feature set creation functions

[jimthompson5802]

Functions to create following standard feature sets:

• raw numeric, with encoded categorical variables (top X categories)
• raw numeric, with one-hot encoding categorical variables (top X categories)
• z scaled numeric with encoded categorical variables (top x categories)
• z scaled numeric with one-hot encoded categorical variables (top x categories)
• min-max scaled numeric with encoded categorical variables (top x categories)
• min-max scaled numeric with one-hot encoded categorical variables (top x categories)