Fix status section out of order problem

multiple status.go in go/cmd/* add status section in vt status server
for system monitoring purpose. However, the problem is they use init
function to do so and may cause potential section out of order problem
on status page if there is another place to also add a new section.

The fix is to introduce a init.go file that manages init methods
for all status.go and schedules methods that updates the same status
page into a single go routine.