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.
Update the Filter class to use "channels" as the canoncial operator
for public stream searches and web-public message fetch narrows,
but keep using "streams" for user-facing text and URLs.
When searching, "channels" does not create any suggestions until
a colon is added and then it shows suggestions with "streams". And
when a search string with channel as an operator is entered, then
it is replaced by "streams" as well.
Part of stream to channel rename project.
Update the Filter class to use "channel" as the canoncial operator
for streams, but keep using "stream" for user-facing text and URLs.
When searching, "channel" does not create any suggestions until
a colon is added and then it shows suggestions with "stream". And
when a search string with channel as an operator is entered, then
it is replaced by "stream" as well.
Part of stream to channel rename project.
Lauryn Menard
afeefuddin