WIP: ProcessStack and read-in of VARIABLE_STRING via gdb api
- fixing #58 (closed): remove parsing of stack and frame via GDB user-output (which will be broken if any frame-filters are active)
- source-name suffix for VARIABLE_STRING read in from cob_module->module_source (this is what cobcd has seen, a later rename could otherwise break it - and we don't need to parse the frames)
- included suggested variant for using the program_id for the suffix instead
- VARIABLE_STRING read in by gdb api (single invocation instead of parsing and concatenating memory dumps)
WIP as it is not tested yet, so only showcasing for now