Add new InputBindResult.ResultCode for no editor

Added a new ResultCode.ERROR_NO_EDITOR for case when there is
no focused editor in the current window. This change should've been included
in Ibf9dab3d9c138b5f04e053d41ee4fd248c78e4da

Bug: 37617707
Fixes: 72913821
Test: Manually check logcats for an activity window:
1. with editor focused
2. with edtior available but not focused (e.g. SearchView)
3. with no editor.
Verified that in all cases, InputBindResult isn't null.

Change-Id: I681b8a452dc7104ca294d5388219cea9ab41e160