[BUGFIX] remove field 'job_function' and correct label 'area' to 'department'

Classes/Domain/Model/Job.php

Classes/Domain/Repository/JobRepository.php

Classes/Service/FrontendFilterService.php

Configuration/TCA/tx_sgjobs_domain_model_job.php

Configuration/TCA/tx_sgjobs_domain_model_job_application.php

Resources/Private/Backend/Partials/Filter.html

Resources/Private/Language/de.locallang_db.xlf

Resources/Private/Language/locallang_db.xlf

Resources/Private/Partials/Job.html

ext_tables.sql