Bug 499752

SUMMARY
The class MyMoneyMoney is an elementary class and is used very often in the source code. Since the contained value is hidden inside, it cannot be displayed directly in debuggers such as gdb, kdevelop or QtCreator, which makes debugging more difficult. Outputs must therefore be generated manually by adding debug outputs, e.g. with `qDebug() << instance.toDouble()` or in the gdb window with `p instance.toDouble()`. It would speed up debugging if there is corresponding support for debuggers. 

STEPS TO REPRODUCE
1. build kmymoney from source (git master branch) with debug information included
2. run 
```
gdb <builddir>/bin/kmymoney
(gdb) b main
(gdb) r
(gdb) b MyMoneyMoney::One
```
3.  inspect debugger output

OBSERVED RESULT
The debugger displays a lot of data, but not the relevant value:
```
(gdb) p MyMoneyMoney::ONE
$1 = {<AlkValue> = {d = {d = 0x87f300}}, _vptr.MyMoneyMoney = 0x7ffff78b18c0 <vtable for MyMoneyMoney+16>, static maxValue = {<AlkValue> = {d = {d = 0x8807e0}}, 
    _vptr.MyMoneyMoney = 0x7ffff78b18c0 <vtable for MyMoneyMoney+16>, static maxValue = <same as static member of an already seen type>, static minValue = {<AlkValue> = {d = {d = 0x880810}}, 
      _vptr.MyMoneyMoney = 0x7ffff78b18c0 <vtable for MyMoneyMoney+16>, static maxValue = <same as static member of an already seen type>, 
      static minValue = <same as static member of an already seen type>, static autoCalc = {<AlkValue> = {d = {d = 0x8807b0}}, _vptr.MyMoneyMoney = 0x7ffff78b18c0 <vtable for MyMoneyMoney+16>, 
        static maxValue = <same as static member of an already seen type>, static minValue = <same as static member of an already seen type>, 
        static autoCalc = <same as static member of an already seen type>, static ONE = {<AlkValue> = {d = {d = 0x87f300}}, _vptr.MyMoneyMoney = 0x7ffff78b18c0 <vtable for MyMoneyMoney+16>, 
          static maxValue = <same as static member of an already seen type>, static minValue = <same as static member of an already seen type>, 
          static autoCalc = <same as static member of an already seen type>, static ONE = <same as static member of an already seen type>, static MINUS_ONE = {<AlkValue> = {d = {d = 0x87f3f0}}, 
            _vptr.MyMoneyMoney = 0x7ffff78b18c0 <vtable for MyMoneyMoney+16>, static maxValue = <same as static member of an already seen type>, 
            static minValue = <same as static member of an already seen type>, static autoCalc = <same as static member of an already seen type>, 
            static ONE = <same as static member of an already seen type>, static MINUS_ONE = <same as static member of an already seen type>}}, 
        static MINUS_ONE = <same as static member of an already seen type>}, static ONE = <same as static member of an already seen type>, 
      static MINUS_ONE = <same as static member of an already seen type>}, static autoCalc = <same as static member of an already seen type>, 
    static ONE = <same as static member of an already seen type>, static MINUS_ONE = <same as static member of an already seen type>}, 
  static minValue = <same as static member of an already seen type>, static autoCalc = <same as static member of an already seen type>, static ONE = <same as static member of an already seen type>, 
  static MINUS_ONE = <same as static member of an already seen type>}
```

EXPECTED RESULT
Instead, the debugger should display the value contained in the named instance
```
(gdb) p MyMoneyMoney::ONE
$1 = 1
```
SOFTWARE/OS VERSIONS
Operating System: openSUSE Leap 15.6
KDE Plasma Version: 5.27.11
KDE Frameworks Version: 5.115.0
Qt Version: 5.15.12