Closes #368 (closed)
Refactored findCodeMarker-method. Return detected points in a separate list instead of appending to the CrossList. Also resolve some clang remarks.
For now, the lines where this function is called just append the return list to the crossList afterwards. But this functionality can be further used when refactoring
refineWithAruco because the detected codes get further processed there (this is currently in progress in #152 (closed) when also using detected candidates).
General code quality
naming conventions are met (see .clang-tidy for detailed information)
no static analyzer warnings in new code parts (e.g., use clang-tidy for checking)
old versions of pet-files are still loadable
Only if changes in UI
new elements are also saved and loaded from pet-file
check if tab order is still correct
all new SpinBoxes are promoted
new keybindings added to