Create the is:followed search operator.
Fetch all messages that are from followed topics
using exists.
Update API documentation and changelog.
Co-authored-by: Kenneth Rodrigues <kenneth.nrk123@gmail.com>
Fixes#27309.
Updates the search suggestions in the web app to use the modern
convention of "channel" and "channels".
Also, updates the "from" search suggestions to use the modern
canonical convention of "sender".
Part of stream to channel rename project.
evykassirer
nimish
Lauryn Menard
evykassirer