Add parameter inlay hints in QtCreator for C++

Add the option to show parameter hints for arguments of C++ function and methods.

I.e. show the parameter names from function / method declaration while calling the function in the editor.

E.g. funtion declaration:

<ret_type> foo(type1 arg1, ...);

In the editor, when the function is called, one would write e.g.:

<ret_type> res = foo(var1, ...);

With parameter hints, the editor will show:

<ret_type> res = foo(arg1: var1, ...);

Notice the arg1: infront of the parameter var1

It is good to make this functionallity optional, since there may be programmers feeling the screen be "cluttered".

 

A good description is available from JetBrains for their IDEs: 

https://www.jetbrains.com/help/idea/inlay-hints.html

In a essence it mimics "named" parameters for C/C++.