Should throw error on reading ill-formed .pet-file (e.g. wrong decimal separator)

We didn't check if the values from the pet file are parsed successfully, which lead to errors. This MR introduces helper methods that check that. I tried my best to divide my changes with commits so one can look at one commit at once when reviewing.

Reviewer Checklist

Formatting

• the pre-build checks succeed

General code quality

• naming conventions are met (see .clang-tidy for detailed information)
• no static analyzer warnings in new code parts (e.g., use clang-tidy for checking)

General usability

• old versions of pet-files are still loadable

Only if changes in UI

• new elements are also saved and loaded from pet-file
• check if tab order is still correct
• all new SpinBoxes are promoted
• new keybindings added to Petrack::keyBindings()

src/util/importHelper.cpp

@@ -140,10 +140,12 @@ bool readBool(const QDomElement &elem, const QString &name, const bool &defaultV
         {
             return false;
         }
-        throw std::domain_error(QString("Could not parse parameter %1 successfully, Value %2. Ill-formed .pet-file.")
-                                    .arg(name)
-                                    .arg(value)
-                                    .toStdString());
+        throw std::domain_error(
+            QString("Could not parse parameter %1 successfully, Value %2, Elem %3. Ill-formed .pet-file.")
+                .arg(name)
+                .arg(value)
+                .arg(elem.tagName())
+                .toStdString());
     }
     return defaultVal;
 }