fileformat: Add support for parsing of archives (static libraries)

Currently, we don't support archives (static libraries) in fileformat. We have separate tool called `ar-extractor` which is able to extract object files out of archive and then we can run decompilation on the extracted files.

It would be nice to incorporate support of archives into `fileformat`. This is going to be hard task because `fileformat` is absolutely not prepared for such change. It expects executable file with ordinary data structures such as import tables, symbols, etc.

We would also get rid of `fileinfo.sh` script if we solved this ticket.

Start by reading the existing fileformat implementation and the separate ar-extractor tool to understand how archive members are extracted before decompilation. Check how fileinfo.sh currently connects these steps. Done means fileformat can parse static-library archives directly and fileinfo.sh is no longer needed.

Written by the indexing model from the issue text.