We have been persisting muting preferences on the back end for
a while, but we haven't been adding them to page_params for the
client to have at reload/startup time.
(imported from commit d9ca68aa0e4d22bfb0e6ce67fc0bc63981175c8b)
If you have two browsers open for the same account, muting in one
browser will now be reflected in the other browser. This got
regressed when changing the approach from collapsing to hiding.
The new code should be less brittle, as we encapsulate re-rendering
in muting.rerender().
(imported from commit 4e65e265b64513d38f518770453b7436cb92b4ca)
Instead of collapsing muted messages, just hide them altogether
in view where it makes sense to hide them.
(imported from commit 1c2c987ff302ceb135a025753cf421b4de1aea71)