Motivation for this change

Adds mat2, a program designed to remove metadata information from a variety of file types. This can be useful for not accidentally revealing personal information when sending files. Below are supported file formats:

• epub
• pdf
• ncx (epub table of contents format)
• tar
• zip
• mpeg
• wav
• gif
• jpeg
• png
• svg
• tiff
• bitmap
• portable pixmap
• css
• html
• plaintext
• mp4
• avi

Upstream is at: https://0xacab.org/jvoisin/mat2/

Added myself as maintainer as well. This is my first package, so if there are any issues with this PR please let me know and I will do my best to correct them. Package was tested on all file types except for:

• ncx
• tiff
• bitmap
• portable pixmap

as I do not have natural versions of these with metadata. Some epub files failed while testing, but I beleive this is due to issues upstream, since the software is officially still in beta.

doCheck = false was set, as there was an issue with internal library detection during the check phase. If there is a known solution to this, please let me know.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.