This commit introduces a new container parameter for functions that
can be used for both compose and edit mode. It provides the function
with information about the context in which it is being used.
We add a new banner informing the user if and when they send a message
to a muted topic / stream. It also has a button to unmute the topic.
Fixes: #24246.
This lets us simplify the long-ish ‘../../static/js’ paths, and will
remove the need for the ‘zrequire’ wrapper.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
