Adds `has_conversation` function in
`pm_conversation.RecentDirectMessages` for checking whether we have in
cache evidence of previous messages in a direct message conversation.
Preparation for #28470.
Co-authored-by: Tim Abbott <tabbott@zulip.com>
This commit renames "huddle" to "direct_message_group" in the
web codebase. It also renames the file - "huddle_data.ts" to
"direct_message_group_data.ts"
Fixes part of #28640
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>