Merge pull request #12280 from rgacogne/ddist-cache-inserted-rules

dnsdist: Add a new chain of rules triggered after cache insertion

diff --cc pdns/dnsdist-tcp.cc
Simple merge

diff --cc pdns/dnsdist.cc
Simple merge

diff --cc pdns/dnsdist.hh
Simple merge

diff --cc pdns/dnsdistdist/dnsdist-tcp-upstream.hh
Simple merge

diff --cc pdns/dnsdistdist/docs/rules-actions.rst
Simple merge