[fix] Analysis tab: only show the beam voltage and current for SEM & FIB streams

We used to show the metadata for all the streams, but until now only SEM
& FIB streams had this information (in some rare cases). Now, SEM
streams have this info almost all the time, and CL streams too, on the
SPARC. However, on the CL streams, it's always the same as the
concurrent SEM stream, so no need to display it too.

Author: pieleric

src/odemis/gui/cont/stream.py

@@ -281,11 +281,14 @@ def _display_metadata(self):
         elif model.MD_DWELL_TIME in md:
             self.add_metadata(model.MD_DWELL_TIME, md[model.MD_DWELL_TIME], 's')
 
-        if model.MD_EBEAM_VOLTAGE in md:
-            self.add_metadata("Acceleration voltage", md[model.MD_EBEAM_VOLTAGE], 'V')
-
-        if model.MD_EBEAM_CURRENT in md:
-            self.add_metadata("Emission current", md[model.MD_EBEAM_CURRENT], 'A')
+        # On the SPARC, the CL streams (eg, spectrum) also have the beam voltage and current metadata,
+        # but it's not helpful to show it, as it's always the same as the associated SEM streams
+        if self.stream.acquisitionType.value in (model.MD_AT_EM, model.MD_AT_FIB):
+            if model.MD_BEAM_VOLTAGE in md:
+                self.add_metadata("Acceleration voltage", md[model.MD_BEAM_VOLTAGE], 'V')
+
+            if model.MD_BEAM_CURRENT in md:
+                self.add_metadata("Emission current", md[model.MD_BEAM_CURRENT], 'A')
 
     def pause(self):
         """ Pause (freeze) SettingEntry related control updates """