Add Status column to server lookup result table

In this column we shown whether the keyserver claims that a key is
expired or revoked. The real status can only be determined after the
key has been imported.

The Columns enum (that was "hidden" in the private class) is replaced
by namespaced static ints because scoped ints is what we need.

(cherry picked from commit bc537d79f98f61b9c6a051b62606135d5f4c32af)

• GnuPG-bug-id: T8042