Move FetchedContentUnserializer from wb.serialization to wb.store

Change-Id: Id2f633ced858d9be10e01bb6edfdfe7fd79af33a
Remove duplicate dependency

Change-Id: I01434c518a131961e373566b251c4c4231e79eb7
Merge "Move FetchedContentUnserializer from wb.serialization to wb.store"
Merge "Remove duplicate dependency"