RSARTE: Better support for generated class operators

Better support for generated methods for C++ classes.
Via the C++ general tab several C++ methods (constructor/equality operator etc.) can be generated automatically
Several improvements and extensions are possible:
- Make these generated operators visible in the project explorer or at least in the properties/operations tab, because
these operators are also part of the class interface.
- Add an option to generate the equality operator and inequality operator as friend instead of as member functions (due to symmetry reasons creating these operators as external methods is preffered above member functions)
- Add for each class attribute an option to exclude this attribute from the equality/inequality operator, so class comparision can be done based on only a subset of the attributes
- Beside equality and inequality operators also operators <, <=, > and >= can be generated automatically
- In C++20 comparision will be updated with the introduction of a "space ship" operator <=>, add support for this operator
- add options to automatically create ostream operator<<
- Based on a user defined base operator, other operators can also be generated automatically, e.g. postfix operator++(int)
based on user defined prefix operator++, addition operator+ based on user defined operator+= etc.
A A::operator++(int) // postfix
{
const auto tmp(*this);
operator++(); // prefix
return tmp;
}

A operator+(const A& a, const A& b)
{
auto tmp(a);
return tmp += b;
}