WIP: Feature/rapid cdn haproxy certificate check

Use minimal haproxy configuration (the normal and quic version) to check each certificate provided by the request or from kedifa.

See https://github.com/haproxy/haproxy/issues/2117

Note: consider doing it on frontend node in the end with a promise; depend on the haproxy used.

Depends on https://lab.nexedi.com/nexedi/kedifa/merge_requests/14

❗ KeDiFa blindly puts certificates from it's store directly on the FS. 💡 So make it not blind and add asserter.