MISC Naming - `_utilize_`

Rename type-specific `dispatch` functions to `utilize`.
REFACTOR `_utilize_dict`, `_utilize_Dict`

Add function `_utilize_dict`. Called by `_validate_dict_structure`.
Replaces `_validate_dict_rules`.

Add function `_utilize_Dict`. Called by `_validate_Dict_structure`.
Replaces `_validate_Dict_rules`.