Draft: Prompt the user for an archive name when using -c without archive name

This MR should resolve https://bugs.kde.org/show_bug.cgi?id=441964

When the -c (or --add) option is specified without an archive name (-f or --autofilename), ark would quit with an error.

Instead, this MR implements the behavior described by the cli help, namely "Query the user for an archive filename and add specified files to it. Quit when finished."

This MR is a WIP, as I'm not 100% this is the right design. (And I'm also having a bit of trouble testing, though I do believe the implementation is correct.)