Updates translated strings in web/ that do not need updates to any
tests. The majority of these strings are also unique to the file/
template that they are in. A few have overlap with one other file.
Some changes here update placeholders/variables in these strings to
no longer use stream so that all the translation updates for this
rename happen at the same time.
The exception to this are cases of "<z-stream>" placeholders in
these translated strings.
Part of the stream to channel rename project.
This commit renames the realm-level setting 'notifications_stream'
to 'new_stream_announcements_stream'.
The new name reflects better what the setting does.
This commit make changes in create stream panel by moving
announce stream option below stream description and adds a
"Stream permissions" section heading just above
"Who can access the stream?" and also rewords the text
"Announce stream".
Also now announce stream option is only shown if the user creating
stream have access to the announcement stream name. When option
is not shown, default behaviour is to announce public and
web-public streams.
Fixes#23327.