EXOSmtpDaneInbound: New resource proposal

[salbeck-sit]

Description

The resource will enable DANE-support for inbound mails to an accepted domain

Proposed properties

DomainName - must be among the Accepted Domains

Special considerations or limitations

Enabling DANE for inbound SMTP relies on enabling DNSSEC for the same domain and subsequently updating the public MX-record
Therefore, enabling support for DANE is not something to be done in a single config.
However, exported configs can show whether DANE-support is enabled and for that reason the resource brings value to the table.