Improve VMs status ping

Currently, all created VMs are ping every 3 seconds:

teamcity-openstack-plugin/cloud-openstack-server/src/main/java/jetbrains/buildServer/clouds/openstack/OpenstackCloudImage.java

Lines 75 to 82 in 1740856

    
           this.executor.scheduleWithFixedDelay(new VerboseRunnable(() -> { 
        
               for (OpenstackCloudInstance instance : getInstances()) { 
        
                   instance.updateStatus(); 
        
                   if (instance.getStatus() == InstanceStatus.STOPPED || instance.getStatus() == InstanceStatus.ERROR) { 
        
                       forgetInstance(instance); 
        
                   } 
        
               } 
        
           }, true), 3, 3, TimeUnit.SECONDS);

This behavior occurs many call to OpenStack API, and logs in platform ; not minor when you have many many many VMs managed by this plugin.

It could be great to reduce this number of call, possible way:

Increade time call
Use an OpenStack API endpoint (if exist) which give status for all VMs ; FYI AWS plugin seems use that, every minute

Using

for (Server s : openstackApi.getNovaServerApi().listInDetail().concat()) {
    System.out.println("DEBUG: " + s.getName() + " = " + s.getStatus());
}

produces only one GET:

GET https://openstack.company.com/v2.1/ec...43/servers/detail

=> Seems achievable

	this.executor.scheduleWithFixedDelay(new VerboseRunnable(() -> {
	for (OpenstackCloudInstance instance : getInstances()) {
	instance.updateStatus();
	if (instance.getStatus() == InstanceStatus.STOPPED \|\| instance.getStatus() == InstanceStatus.ERROR) {
	forgetInstance(instance);
	}
	}
	}, true), 3, 3, TimeUnit.SECONDS);