Not enabled by default yet. Enables dumping of dns traffic.
Fix DNSTAP issues in build and unit tests.
Fool rpmlint to accept dnstap relative path. Rpmlint emited error
hardcoded-library-path on dnstap path. It is not system-wide library,
workaround by using variable.
Add dnstap-read utility to utils. When dnstap is enabled,
dnstap-read will be part of utils. Disadvantage is all utilities would have
dependency on protobuf library, including host and dig.
Resolves: #1564776
