Step Out button should complete the current function instead of discarding it

[olivier-ploton]

Hello.

The 'step out' button discards the end of the current functions and returns. It is a subjective point, but according to me this is not the usual behavior: googling 'step out' gives me for example these answers from StackOverflow: (https://stackoverflow.com/questions/52368009/what-is-the-difference-between-step-in-step-out-and-step-over) and
(https://stackoverflow.com/questions/24712690/step-out-of-current-function-with-gdb).

Moreover, discarding by error the end of a function often leads to memory leaks, inconsistent states and crashes (e.g. when C++ destructor calls are forgotten at the end of a function).

I propose to change the 'step out' behaviour to the usual one. If you agree, you can have a look at the (very small) pull request I send to you.

Sincerely.