core: Renamed StorageDomainDAO.getStorageDomainByTypeAndPool

The method's parameters types are clear enough, so there's no need to
include them also in the method's name.

Change-Id: Iffc63c3a22488e459be3c9beac9dd5d0163f0d12
Related-To: https://bugzilla.redhat.com/1085398
Signed-off-by: Idan Shaby <ishaby@redhat.com>