Several fixes

A container branch for the fixes of several issues I encountered while rolling out the current SaQC on the SEEFO pipeline.

Not sure, if this needs a real review, but as some of the changes touched code I am not completely familiar with, maybe you, @palmb and @luenensc want to have a look anyhow?

saqc/core/history.py

@@ -247,8 +247,9 @@ class History:
             raise ValueError("Index does not match")
 
         n = len(self.columns)
-        value_hist = value.hist
-        value_mask = value.mask
+        # don't overwrite the `.columns` of the input down the line
+        value_hist = value.hist.copy(deep=False)
+        value_mask = value.mask.copy(deep=False)
 
         if not force:
             value_hist = value_hist.iloc[:, n:]