Further process ldd output

[stefan6419846]

Currently, we just forward the output of ldd for ELF binaries from a subprocess and print it to stdout directly. This probably can be improved.

Due to already using the ScanCode toolkit, I evaluated the elf-inspector tool, but this currently lacks important features as it does not provide the full dependency paths (to decide whether the originate from the OS or whether they are shipped with the package itself) and somehow omits the libc dependency in some cases: aboutcode-org/elf-inspector#4.