Add copy link button to events

[SamuelmdLow]

We should make it really easy for people to share events from our events calendar because that might bring more people to the page

[SamuelmdLow]

The clipboarded link should always include the month, year, category, and (obviously) event parameters. The date parameters are important because it means the link will still take you to the time the event was set to occur in the future. The category is just cause showing all categories together is ugly.