[AGIPD] Split AGIPDCtrl function for clear code and adding tests later.

Based on changes in MR : https://git.xfel.eu/detectors/pycalibration/-/merge_requests/652

This MR is a preparation for the next MR for adding unit tests https://git.xfel.eu/detectors/pycalibration/-/merge_requests/646

Description

• Separate get_gain_setting() and get_acq_rate() into two different functions which read the gain_settings and acquisition rate using two different methods.

• Small refactors:

  • correct hint typing for get_gain_mode()
  • correct the doc string for get_num_cells()
  • correct the doc string for AGIPDCtrl()

How Has This Been Tested?

Relevant Documents (optional)

Types of changes

Checklist:

• I added tests where appropriate. In a separate MR: https://git.xfel.eu/detectors/pycalibration/-/merge_requests/646

Reviewers

@calibration

src/cal_tools/agipdlib.py

@@ -88,7 +88,7 @@ class AgipdCtrl:
             # It is desired to loose precision here because the usage is
             # about bucketing the rate for managing meta-data.
 
-            return round(float(self.run_dc[rep_rate_src].as_single_value()), 1)
+            return round(float(self.run_dc.get_run_value(*rep_rate_src)), 1)
 
         train_pulses = np.squeeze(
             self.run_dc[
@@ -128,11 +128,11 @@ class AgipdCtrl:
             return
 
         if "gain.value" in self.run_dc.keys_for_source(self.ctrl_src):
-            return self.run_dc[self.ctrl_src, "gain.value"].as_single_value()
+            return self.run_dc.get_run_value(self.ctrl_src, "gain.value")
 
-        setupr = self.run_dc[self.ctrl_src, "setupr.value"].as_single_value()
-        pattern_type_idx = self.run_dc[
-            self.ctrl_src, "patternTypeIndex.value"].as_single_value()
+        setupr = self.run_dc.get_run_value(self.ctrl_src, "setupr.value")
+        pattern_type_idx = self.run_dc.get_run_value(
+            self.ctrl_src, "patternTypeIndex.value")
 
         if (setupr == 0 and pattern_type_idx < 4) or (
                 setupr == 32 and pattern_type_idx == 4):
@@ -194,7 +194,7 @@ class AgipdCtrl:
             voltage_src[1] in self.run_dc.keys_for_source(voltage_src[0])
         ):
 
-            return self.run_dc[voltage_src].as_single_value(atol=1, reduce_by='max')
+            return self.run_dc.get_run_value(*voltage_src)
         else:
             print(
                 "WARNING: Unable to read bias_voltage from"