This allows easier reuse of certain reoccurring behaviours,
such as authorization.
The AuthenticatedLdpHandler is no longer required
since it is a combination of parsing and authorization.
This did require a small change to the OperationHandler interface.
* feat: Implement HEAD request support
* feat: Integrate HEAD handler with other code
* fix: Improve test by using arrayifyStream
* fix: Use Promise chaining
* refactor: Unwrap destroy stream promise
