Add code to manipulate the items in OpenSSL::Ordinals

This means adding the capability to add new items, to invalidate and
revalidate all the items, and to update the file it came from, as well
as the possibility to create new items from other data than a line
from said file.

While we're at it, we throw in a couple of useful filters.

Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/7191)