This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
FEATURE: clicking envelope takes you to inbox
Suggested messages works somewhat like suggested topics.
- New show up first (in either group inbox or inbox)
- Then unread (in either group inbox or inbox)
- Finally "related" which are messages with same participants as the current pm.
