Prior:
Entering `test after:5` and then removing the 5 via the search text field would result in the UI not updating
After:
UI updates after half a second
Removing it from the UI, removes it from the search field immediately.
Change the regex to detect filter words. This now matches what happens in search.rb, which gives a lot more flexibility (such as iterating over multiple `in:` terms)
Return [] when searchTerm is empty
Move .trim() to this.set('searchTerm', searchTerm) so it doesn't run twice (which was very obvious when watching the search term field)
More refactoring to make this a bit less complex
Update code based on review comments
FEATURE: Add common `in:` options
