add kvfilter type that regroups very frequently used filters

hcl2template/types.kv.go

@@ -6,3 +6,19 @@ type KeyValue struct {
 	Key   string
 	Value string
 }
+
+type KVFilter struct {
+	Filters map[string]string
+	Filter  []KeyValue
+}
+
+func (kvf *KVFilter) Prepare() error {
+	for _, filter := range kvf.Filter {
+		kvf.Filters[filter.Key] = filter.Value
+	}
+	return nil
+}
+
+func (kvf *KVFilter) Empty() bool {
+	return len(kvf.Filters) == 0
+}