Class for representing, retrieving, validating, and processing a VMC Certificate
=head1 INPUTS
These values are used as inputs for lookups and verifications, they are typically set by the caller based on values found in the message being processed
=head2 ascii_lines
is=rw required
Raw data of the Cert contents
=head1 ATTRIBUTES
These values are derived from lookups and verifications made based upon the input values, it is however possible to override these with other values should you wish to, for example, validate a record before it is published in DNS, or validate an Indicator which is only available locally
=head2 chain
is=rw required
Back reference to the chain
=head2 errors
is=rw
=head2 filename
is=rw
Filename of temporary file containing the cert
=head2 index
is=rw required
Index of this certificate in the chain
=head2 indicator_asn
is=rw
Parsed ASN data for the embedded Indicator
=head2 is_valid
is=rw
Is this a valid Cert?
=head2 is_valid_to_root
is=rw
Could we validate this certificate to the root certs, set by Mail::BIMI::VMC::Chain->is_valid
=head2 validated_by
is=rw
Root and/or intermediate certificate in the chain used to verify this certificate