bindings-gpgme does not expose all properties in gpgme_key_t and gpgme_subkey_t

[dxtr]

According to https://www.gnupg.org/documentation/manuals/gpgme/Key-objects.html there are some properties missing from gpgme_key_t and gpgme_subkey_t.

The issue is that these are bitfields which seem to be pretty annoying to deal with.

I am working on a solution for this but I suspect it'll be awful so how would you go about sorting this out?