backported some of the v0.23.0 form validators, fixes and tests

forms/realtime_subscribe.go

@@ -19,5 +19,6 @@ func NewRealtimeSubscribe() *RealtimeSubscribe {
 func (form *RealtimeSubscribe) Validate() error {
 	return validation.ValidateStruct(form,
 		validation.Field(&form.ClientId, validation.Required, validation.Length(1, 255)),
+		validation.Field(&form.Subscriptions, validation.Length(0, 1000)),
 	)
 }