This diff has been extracted from c2f7ccab0e
See https://github.com/ooni/probe/issues/2096
While there, export DecodeReply to decode a raw reply without
interpreting the Rcode or parsing the results, which seems a
nice extra feature to have to more flexibly parse DNS replies
in other parts of the codebase.
Shared data structures and interfaces. We include in this
package the most fundamental types. Use go doc to get
more thorough documentation about what is inside this package
and when to put a type inside this package.