Follow-ups from #18015:

• add support for adding and editing action entries
• when we discard changes or save, it would be cool if we could stay on the same page
• allow customizing the folder entry before adding it (current workaround is to add it, then edit it)
• improve UI for setting icon (reuse UI from Improve Profile.Icon UI in settings #17965)
• Windows 10 doesn't like grids (See note below)
  • PR [Windows 10] Fix layout in New Tab Menu page #18424
  • Upstream: ListView with inner Grid does not respect ColumnDefinition width on Windows 10 microsoft-ui-xaml#10300

Windows 10

Bug bash 1/21 notes

• narrow window can cut off buttons