Clean up/remove event timestamp checking code from GlOutsideDirective

The GlOutsideDirective now uses event capturing, which should mean that its timestamp-checking behaviour can be removed.

This would mean:

• Removing src/directives/outside/get_event_like_time_stamp.js
• Removing src/directives/outside/LICENSE
• Simplifying the data structures and logic related to timestamp comparisons
• Adding a Cypress test to verify that the original purpose for the timestamp checking code is satisfied by just using event capture. (Jest is insufficient for this.) Added a comment to { capture: true } because it is not testable, neither with Jest nor Cypress, as described in this discussion.

For reference, here's the discussion which led this timestamp checking in the first place.