Consolidate words into SuggestedWordInfo

We can't get rid of SuggestedWordInfo because it conveys
the information about whether a suggestion is outdated or
not. It is always created anyway. So it makes sense not
to have separate lists and to just keep everything in the
SuggestedWordInfo object.

Change-Id: Idd79dc267d97633901d3d2869da457736963e178