rc.d/*: Use startmsg instead of echo on start messages

By rc.conf(5), setting rc_startmsgs="NO" should silence start messages.

Fix a few rc scripts by using startmsg.

PR: 255207
Reported by: Jose Luis Duran <jlduran@gmail.com>
Reviewed by: imp, 0mp
Approved by: imp (src)
Differential Revision: https://reviews.freebsd.org/D34514