Refactor stream store content lists and objects
Make the stream store simpler by storing all content objects in
contents, ditching the
shares. There are list references to those from each content.
This allows looking up replies and shares from the contents object. This fixes the
current issues in the reply button sometimes not working.
currentContentIds since it refers to the stream current
top level content id's. Add
allContentIds to keep a reference to locally stored content