[BUGFIX] Add domain model validators only once

If a domain model validator is present and a controller
action accepts this domain model as argument, the validator
is added twice to the validation tree.

It is added in
ValidatorResolver::buildMethodArgumentsValidatorConjunctions()
and in ValidatorResolver::addCustomValidators() which is called
from ValidatorResolver::getBaseValidatorConjunction()

Both methods are called when building the validation tree in
ActionController::initializeActionMethodValidators()

Resolves: #52607
Releases: master, 6.2
Change-Id: Ic1674bacfb027840d9b8fcd1d66586ebb0e75ad6
Reviewed-on: http://review.typo3.org/36915


Reviewed-by: Patrick Schriner <patrick.schriner@diemedialen.de>
Tested-by: Patrick Schriner <patrick.schriner@diemedialen.de>
Reviewed-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>
Tested-by: Andy Grunwald <andygrunwald@gmail.com>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Helmut Hummel <helmut.hummel@typo3.org>
Tested-by: Helmut Hummel <helmut.hummel@typo3.org>