Extend dnstap option to support update messages
Description
The 'dnstap' option currently supports messages for client, resolver, auth, forwarder, and all. It is desirable to also capture dynamic DNS update messages via dnstap output. Although update messages are technically a sub-type of query messages via the opcode, it is preferable to categorize them as their own type with respect to the dnstap output. This would allow a dnstap option configuration grammar of:
dnstap { ( all | auth | client | forwarder | resolver | update ) [ ( query | response ) ]; ... };
Request
See the attached 'git diff' for the modifications to the BIND v9_11 branch to support this extension to the dnstap option.