fix: templates are build from DB

...en/src/main/java/unipotsdam/gf/modules/tasks/TaskDAO.java

...n/src/main/java/unipotsdam/gf/modules/tasks/TaskView.java

...insamforschen/src/main/webapp/project/js/tasks-student.js

.../test/java/unipotsdam/gf/interfaces/ActivityFlowTest.java

.../java/unipotsdam/gf/modules/tasks/GroupPhaseTaskTest.java

gemeinsamforschen/src/test/resources/database/fltrail.sql