feat: Sharing improvements (#1388)

* add migrations

* first pass at API

* feat: Updated share dialog UI

* tests

* test

* styling tweaks

* feat: Show share state on document

* fix: Allow publishing share links for draft docs

* test: shares.info

app/models/Event.js

@@ -17,6 +17,7 @@ class Event extends BaseModel {
     name: string,
     email: string,
     title: string,
+    published: boolean,
   };
 
   get model() {