connection request: add conversation id

This patch adds conversation ID to the connection type
when sending a connection request. It will be used by
the iOS notification extension to detect which conversation
to start.

https://git.jami.net/savoirfairelinux/jami-client-ios/-/issues/345
Change-Id: I164017db6883bfb22c49fa8f9d5f802bcd8e0a93