Improve readability of the search results activity

Is your feature request related to a problem? Please describe.
The search results activity, accessible from the searchbox on the main activity, is barebones and lacks useful information.

Describe the solution you'd like
Add to the Activity:

• a menu to reorder notes by: due date, last edit date, alphabetic, ...
• a toggle to temporarily hide notes without a due date from the results
• a sorted date view when ordering notes by due date, with "today", "tomorrow", "next week", ...

Idea: move this menu, which is W.I.P.,

from ActivityMain to ActivitySearch, and have the items rerun the query with the selected sorting

the code should update this function in FragmentSearch.java:

	protected String getSortOrder() {
		return Task.Columns.DUE;
	}

Start in FragmentSearch.java at getSortOrder(), then inspect the existing W.I.P. menu in ActivityMain and the ActivitySearch implementation. Move or adapt the menu so it supports the requested sort choices, hiding notes without due dates, and grouped date views, with each selection rerunning the search query. Done means the search activity exposes these controls and displays results using the selected ordering or filter.