[dnstap] Adding response policy information in dnstap

[Pieter Lexis]

Hi Chris,

I haven't digested this fully, but there's a small error in the .proto:

On 2/1/21 7:59 PM, Chris Mikkelson wrote:
> 
> 	// Policy: information about any name server operator policy
> 	// applied to the processing of a DNS message.
> 	message Policy {
> 	
> 	    // The matched value. Format depends on the matched feature .
> 	    optional bytes value = 2;
> 	}

Should be '5'.

Cheers,

Pieter
-- 
Pieter Lexis
PowerDNS.COM BV -- https://www.powerdns.com