Issue #108 - Fix cascade soft delete with newly installed Extension

[nitrajka]

I also fixd unappropriate db column names and variables in entities Resolves #108

[ZoltanOnody]

• [x] UnsubscribeController riadok 24 $language = $registration->getLanguages();
• [x] ConfirmRegistrationController riadok 23
• [x] Default controller riadok 69: $registration->setLanguages($attendeeLanguage);
• [x] AddMockedDataCommand riadok 232

[ZoltanOnody]

v Registration prepis setEvents na setEvent a potom si oprav chyby v

• [x] DefaultController riadok 105
• [x] AddMockedDataCommand riadok 222
• [x] ConfirmRegistraionController riadok 24
• [x] UnsubsribeController riadok 25
• [x] UnsubsribeController riadok 26