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

server/migrations/20200723055414-add-published-to-shares.js

@@ -0,0 +1,20 @@
+'use strict';
+
+module.exports = {
+  up: async (queryInterface, Sequelize) => {
+    await queryInterface.addColumn('shares', 'published', {
+      type: Sequelize.BOOLEAN,
+      allowNull: false,
+      defaultValue: false
+    });
+
+    await queryInterface.sequelize.query(`
+      update shares
+      set "published" = true
+    `);
+  },
+
+  down: async (queryInterface, Sequelize) => {
+    await queryInterface.removeColumn('shares', 'published');
+  }
+};