text: Title: Feature: Add get_selection() to MycroftSkill class
  Body: A common need for Skill developers is to present a list of options to the user and ask them to make a selection. This is possible using a combination of existing methods, however it requires each developer to work out their own pattern. Adding a standard method will make this easier for developers and provide a more consistent experience for users.
  
  The current method generally involves:
  1. Take list of items
  2. Generate question dialog using [`join_list()`](https://mycroft-core.readthedocs.io/en/latest/source/mycroft.util.format.html?highlight=list#mycroft.util.format.join_list)
  3. [`get_response()`](https://mycroft-core.readthedocs.io/en/latest/source/mycroft.html?highlight=get_response#mycroft.MycroftSkill.get_response) from user
  4. validate response checking for:
      - fuzzy match of list item
      - ordinal or number eg "third item", or "number two"
  5. return selected item, or execute `on_fail` callback