Add runtime content check for "overrides" and pinned libraries

When we are in a steamrt container we log the content of the "/overrides" folder. Otherwise, if we are not in a container, we log the content of both "pinned_libs_32" and "pinned_libs_64".

I implemented ensure_overrides_cached and ensure_pinned_libs_cached directly in system-info.c because they were relatively small functions. If you preferred to have them in another separated file (and with a struct like SrtPinnedLibs for example) I'll move them.

This MR covers the task T16825 and T16849