We fix the improper authorization by duplicating the check done by
the private method EntryController::checkUserAction().
We also replace the ParamConverter used to get the requested Entry with
an explicit call to EntryRepository in order to prevent a resource
enumeration through response discrepancy. Thus, we get the same
exception whether the requested resource does not exist or is not owned
by the requester.
Fixes GHSA-qwx8-mxxx-mg96
Signed-off-by: Kevin Decherf <kevin@kdecherf.com>