(core) Add additional org items to AppHeader

Summary:
Adds links to manage team and go to billing account in
the org menu (opened by clicking the dropdown in the
top-left corner of Grist). Tweaks some wording of items
in both AppHeader and AccountWidget, and adds a link
to create a new team site to the Site Switcher in both
menus.

Also tweaks the UI of UserManager by adding
an animation when the manager is opened from the
doc access dialog.

Test Plan: Browser tests.

Reviewers: dsagal

Reviewed By: dsagal

Subscribers: dsagal

Differential Revision: https://phab.getgrist.com/D3121

test/nbrowser/gristUtils.ts

@@ -1682,7 +1682,7 @@ async function openAccountMenu() {
   // Since the AccountWidget loads orgs and the user data asynchronously, the menu
   // can expand itself causing the click to land on a wrong button.
   await waitForServer();
-  await driver.findWait('.test-usermenu-org', 1000);
+  await driver.findWait('.test-site-switcher-org', 1000);
   await driver.sleep(250);  // There's still some jitter (scroll-bar? other user accounts?)
 }