Add CTA buttons to all event pages

[mattstratton]

Expected behavior

I should see the sharing buttons, as well as the other CTA buttons ("Register", etc) on all pages for an event, not just the welcome page.

Actual behavior

They only show up on the welcome page.

Suggested fix

We could a row to the top with them before the {{ Content}} stuff, or perhaps even add an event-level sidebar to the right, since we have the screen space (which could include CTA stuff, sharing, and maybe more?)

[bridgetkromhout]

If we do an event-level sidebar that might be a nice place for the event's tweet stream.

[jduv]

I could probably come up with some ideas for this and knock it out if folks are open to that.

[mattstratton]

@jduv I'll bump this up in the roadmap if you want to take a swing at it.

[jduv]

Thanks @mattstratton, Planning on working on this tomorrow.