feat: onCreateSet

Add support for onCreateSet with validation.
- If a filter is not provided or a status is not set, a default filter of `status = running` is used.
- update `filters` field to be a slice instead of a string
- add dryRunValidation call to validate fields

plugin/service/host/const.go

@@ -5,7 +5,7 @@ package host
 
 const (
 	// ConstListInstancesFilter refers to a Google Cloud SDK filter to search for instances
-	ConstListInstancesFilter = "filter"
+	ConstListInstancesFilter = "filters"
 
 	// ConstInstanceGroup refers to the name of a Google Cloud instance group
 	ConstInstanceGroup = "instance_group"