Before this commit, when composer had some text content in
multi-line, arrow up/down was not jumping to previous/next
line.
This happens because the navigable list is active even when not
shown, and was preventing all keydown events.
This commit fixes the issue by limiting handling of keydown
events of navigable list to when it is shown.
Also fixes a bug where the quick edit of last message was triggered
when composer text was non-empty with ArrowUp. This should only
be triggered when the composer text input is empty.
closesodoo/odoo#120657
Signed-off-by: Sébastien Theys (seb) <seb@odoo.com>