Promote sorting to note list UI

### What

Add a new UI element to the note listing display to change sort criteria without going to Settings. This would apply to both the web UI and the iOS app, which are the main ways I use Simplenote.

It would make sense to me to have this as a submenu in the top-level hamburger menu, or as a new menu next to the “new note” icon.

### Why

With large numbers of notes, title conventions can be very helpful in keeping things organized. I use a convention where each note has a category as the first word. Sorting notes alphabetically is a good way to see and find related notes. But usually when I am working on notes the “most recently edited” order is what I want.

I find myself going to Settings to change the ordering criteria quite frequently, so it would be great to have a way to do this with fewer taps.

Currently it takes 7 taps to change the ordering and return to the list view. I can easily imagine this being 2 taps if it was a new menu at the top level, or 3 if it was in the hamburger menu (and changing the sort order automatically closed the menu).

Start by reviewing the note listing UI and the existing Settings sort-order control in the iOS app. Determine how the requested control should work in the note list, including the hamburger menu or new-note menu placement. Done means users can change sorting from the note list in both the iOS and web experiences.

Written by the indexing model from the issue text.