Dev: trigger signal issues handled at acquire (#864)

* if blocking and handling sync, only master gets blocking acq, slaves get non blocking as they are first and so dont get status or error caught when slaves dont get trigger (due to not connected etc) and acq returns with slaves still in waiting status. so check status of all in blocking acq

* for all dets with sync, ensure atleast one master when starting acq

* docs updated about sync

python/slsdet/detector.py

@@ -1673,6 +1673,11 @@ class Detector(CppDetectorApi):
     def sync(self):
         """
         [Jungfrau][Moench] Enables or disables synchronization between modules.
+
+        Note
+        ----
+        Sync mode requires at least one master configured. Also requires flatband cabling between master and slave with termination board.
+
         """
         return self.getSynchronization()