Change output of detectExcursion() to align with "events" tibble standard

[nickmckay]

This entails:

• renaming/updating the event probabilities to: event_probability(_positive, _negative, _either, _both)
• renaming null_probability to include: null_probability(_positive, _negative, _either, _both)

[nickmckay]

I think this is now working properly in the standardize-detectExcursion branch