Track gdb callstack to in UI

**Is your feature request related to a problem? Please describe.**
Stepping up or down in the callstack via the gdb input pane (i.e. issuing the 'up' or 'down' commands) is not reflected in the UI.

**Describe the solution you'd like**
When switching a callstack in gdb, the UI would notice and switch its view too.

**Describe alternatives you've considered**
One can always click on the UI to select the correct the level in the callstack. But having this automatic would be convenient.