Convert formatting automatically to f-strings

Automatically convert formatting with the following call:
flynt -ll 2000 -v frappy*
Result: 303/381 auto-converted.
Failing conversions will be looked at manually in a follow-up commit.

Change-Id: Icd996b27221202faccc15af78e0380cf52ee37f2
Reviewed-on: https://forge.frm2.tum.de/review/c/secop/frappy/+/30900
Tested-by: Jenkins Automated Tests <pedersen+jenkins@frm2.tum.de>
Reviewed-by: Georg Brandl <g.brandl@fz-juelich.de>
Reviewed-by: Alexander Zaft <a.zaft@fz-juelich.de>

frappy_demo/modules.py

@@ -74,7 +74,7 @@ class Switch(Drivable):
 
     def write_target(self, value):
         # could tell HW
-        self.status = (self.Status.BUSY, 'switching %s' % value.name.upper())
+        self.status = (self.Status.BUSY, f'switching {value.name.upper()}')
         # note: setting self.target to the new value is done after this....
 
     def read_status(self):
@@ -284,8 +284,7 @@ class Label(Readable):
 
         dev_ts = self.DISPATCHER.get_module(self.subdev_ts)
         if dev_ts:
-            strings.append('at %.3f %s' %
-                           (dev_ts.read_value(), dev_ts.parameters['value'].datatype.unit))
+            strings.append(f"at {dev_ts.read_value():.3f} {dev_ts.parameters['value'].datatype.unit}")
         else:
             strings.append('No connection to sample temp!')
 
@@ -299,7 +298,7 @@ class Label(Readable):
                 state = 'Persistent' if mf_mode else 'Non-persistent'
             else:
                 state = mf_stat[1] or 'ramping'
-            strings.append('%s at %.1f %s' % (state, mf_val, mf_unit))
+            strings.append(f'{state} at {mf_val:.1f} {mf_unit}')
         else:
             strings.append('No connection to magnetic field!')