New Command Line interface

• Introduce a new command-line interface allowing to use microphone recognition from the command line, with the recognize and listen commands (thanks to @Hummer12007), keeping older command backwards compatibility.
• Update the CSV export format in order to introduce new "track_key", "release_year" and "genre" columns (thanks to @tyd), where track_key is an identifier internal to the Shazam database.
• Allow exposing song metadata through the standard DBus MPRIS interface (thanks to @Hummer12007).
• Improve source code structure in order to split the dual CLI/GUI parts from the core thread communication and fingerprinting parts and from other platform-dependant utility code.
• Update certain dependent crates to more recent minor versions, among other possible things in order to accept a higher LibreSSL version.
• Add the program version without the program help output (see the -h or -V, --version options).
• Add a Polish translation (thanks to @qarmin).
• Update the French translation according to recent changes.