CLOUDSTACK-6365: support virtual host and ssl in rabbitMQ event bus

with this fix, virtual host on the AMQP server can be specified. Also
SSL can be used for connection between management server and AMQP
servers.
CLOUDSTACK-6253: Optimizing VR alerts getting algorithm In addition to this a new configuration parameter is added router.alerts.check.interval defaulted to 30minutes to check for alerts in Virtual Router
CLOUDSTACK-6366: add vgpuTypes details  in vgpu_types table.